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. $& V) Q N BS TECHNICAL NOTE 986

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U.S. DEPARTMENT OF COMMERCE/ National Bureau of Standards

NBS Special Foreign

Currency Program

in Yugoslavia 1973-1978
NATIONAL BUREAU OF STANDARDS

The National Bureau of Standards1 was established by an act of Congress March 3, 1901. The

Bureau's overall goal is to strengthen and advance the Nation's science and technology and

facilitate their effective application for public benefit. To this end, the Bureau conducts

research and provides: (1) a basis for the Nation's physical measurement system, (2) scientific and technological services for industry and government, (3) a technical basis for equity in trade, and (4) technical services to promote public safety. The Bureau's technical work is performed by the National Measurement Laboratory, the National Engineering Laboratory,

and the Institute for Computer Sciences and Technology.

THE NATIONAL MEASUREMENT LABORATORY provides the national system of

physical and chemical and materials measurement; coordinates the system with measurement

systems of other nations and furnishes essential services leading to accurate and uniform

physical and chemical measurement throughout the Nation's scientific community, industry,

and commerce; conducts materials research leading to improved methods of measurement,

standards, and data on the properties of materials needed by industry, commerce, educational

institutions, and Government; provides advisory and research services to other Government

Agencies; develops, produces, and distributes Standard Reference Materials; and provides

calibration services. The Laboratory consists of the following centers:

Absolute Physical Quantities2 — Radiation Research — Thermodynamics and

Molecular Science — Analytical Chemistry — Materials Science. THE NATIONAL ENGINEERING LABORATORY provides technology and technical

services to users in the public and private sectors to address national needs and to solve national problems in the public interest; conducts research in engineering and applied science

in support of objectives in these efforts; builds and maintains competence in the necessary

disciplines required to carry out this research and technical service; develops engineering data and measurement capabilities; provides engineering measurement traceability services; develops test methods and proposes engineering standards and code changes; develops and

proposes new engineering practices; and develops and improves mechanisms to transfer

results of its research to the utlimate user. The Laboratory consists of the following centers:

Applied Mathematics — Electronics and Electrical Engineering2 — Mechanical

Engineering and Process Technology2 — Building Technology — Fire Research —

Consumer Product Technology — Field Methods.

THE INSTITUTE FOR COMPUTER SCIENCES AND TECHNOLOGY conducts

research and provides scientific and technical services to aid Federal Agencies in the selection, acquisition, application, and use of computer technology to improve effectiveness and

economy in Government operations in accordance with Public Law 89-306 (40 U.S.C. 759), relevant Executive Orders, and other directives; carries out this mission by managing the Federal Information Processing Standards Program, developing Federal ADP standards

guidelines, and managing Federal participation in ADP voluntary standardization activities; provides scientific and technological advisory services and assistance to Federal Agencies; and

provides the technical foundation for computer-related policies of the Federal Government.

The Institute consists of the following divisions:

Systems and Software — Computer Systems Engineering — Information Technology.

'Headquarters and Laboratories at Gaithersburg, Maryland, unless otherwise noted; mailing address Washington, D.C. 20234.

2 Some divisions within the center are located at Boulder, Colorado, 80303.

The National Bureau of Standards was reorganized, effective April 9, 1978.

.,««——

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SEP 2

NBS Special Foreign Currency

Program in Yugoslavia 1973-1978

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Doris M. Bluebond,

Robert S. Marvin,

and H. Steffen Peiser

Office of the Director

National Bureau of Standards

Washington, D.C. 20234

y flEAU

U.S. DEPARTMENT OF COMMERCE, Juanita M. Kreps, Secretary

Dr. Sidney Harman, Under Secretary

Jordan J. Baruch, Assistant Secretary for Science and Technology

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director

Issued September 1978
Library of Congress Catalog Card Number 78-600093

National Bureau of Standards Technical Note 986

Nat. Bur. Stand. (U.S.), Tech. Note 986, 75 pages (Sept. 1978) CODEN: NBTNAE

U.S. GOVERNMENT PRINTING OFFICE

WASHINGTON: 1978

For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402

Stock No. 003-003-01977-1 Price $2.50

(Add 25 percent additional for other than U.S. mailing).

KOttH
FOREWORD

This Publication reviews the National Bureau of Standards Special

Foreign Currency Program in Yugoslavia since January 1973. The

project descriptions presented here will help scientists and

scientific administrators form opinions on the value of such programs,

and help the more general reader examine an example of international

cooperation and its success in contributing to the general betterment

of the two countries involved and in improving international

scientific relationships

Grants from a Joint Fund, to which the U.S. and Yugoslavia

contribute equally, are made for research by Yugoslav scientists

working in Yugoslav institutions. Projects are approved by the

Yugoslav Federal Administration for International Scientific,

Educational, Cultural and Technical Cooperation and certain U.S.

Scientific and Technological Agencies. Although the NBS allocations

to the Joint Fund have now been fully committed and expended, an

agreement between Presidents Carter and Tito to supplement the funding

brings expectation of program continuation.

111
All the projects funded under this Program are summarized in this

report. The summaries list the project goals, some major results, the

publications which resulted from the specific support under this

Program and the names of the NBS monitor and the principal

investigators. From the NBS viewpoint the Program has been

scientifically productive and has contributed to NBS mission and

programmatic objectives. We understand that Yugoslav officials have

concluded, in part from the previous report (Technical Note 753) , that

our collaborative program has contributed to their own goals as well.

Further, we consider that opportunities abound for a long

continuing program of mutual interest. NBS intends to continue to

explore these opportunities and we trust that the good technical

cooperation that has developed under this program will continue and be

strengthened in the future.

Ernest Ambler

Director

IV

mora
TABLE OF CONTENTS Page(s)

INTRODUCTION 1

STANDARD REFERENCE MATERIALS

L. Kosta/P. D. LaFleur "Determination of Impurity Levels

in Analytical Grade and Ultrapure Chemicals by Activation

Analysis Using Triga Reactor" 7

M. Branica/J. K. Taylor "Electroanalytical Determination

of Trace Elements" 11

MATERIALS MEASUREMENT METHODS AND STANDARDS

R. Blinc/D. H. Reneker "Development and Application of

Ultrasensitive Magnetic Resonance Methods" 15

I. Piljac/J. K. Taylor "Electrochemical Study of Metal

Ion-ligand Interaction in Nonacqueous Solutions by

Investigation of Electro-chemical Property of Ligand" 21

K. F. Zmbov/J. W. Hastie "Mass Spectrometric Studies

of High Temperature Equilibria" 25

PROPERTIES OF MATTER

A. Bonefacic/R. P. Reed "X-ray Diffraction and

Electromicroscopic Studies on Aluminum and on the

Metastable Phases of Aluminum Base Alloys,

Obtained by Rapid Quenching from the Melt" 31

N. Konjevic/W. L. Wiese "Stark Broadening of Spectral

Lines in Plasmas" 37

V. Vujnovic/W. L. Wiese "Measurement of f-values in

Ultraviolet and Visible Region and Study of Continuous

Emission of Hydrogen near the Balmer Limit" 4 3

V. V. Urosevic/G. Dunn "Electron-atom Excitation Cross

Section Measurements " 49

EXPLORATORY RESEARCH

V. Pravdic/W. Haller "Bulk Composition and Surface

Properties of Glass" 51

M. Sunjic/J.W. Gadzuk "Theoretical Investigations

on Physical Surfaces" 57
Page(s)

J. Slivnik/T. D. Coyle "Syntheses and Properties of

Fluoride Complexes" 59

COMPUTER SCIENCE AND TECHNOLOGY

Z. Damjanovic/T. N. Pyke, Jr. "A Modular Computer System

for Real-Time Data Reduction and Control in

Biomedical Experiments" 63

NULCEAR AND RADIATION TECHNOLOGY

I. Draganic/W. L. McLaughlin "Radiation Dosimetry and

Radiation Chemistry" 67

APPENDIX I - SFCP (PL-480) BACKGROUND HISTORY 71

APPENDIX II - INDEX OF INSTITUTES 73

APPENDIX III - ALPHABETIC LIST OF PRINCIPAL INVESTIGATORS . 74

APPENDIX IV - ALPHABETIC LIST OF NBS MONITORS 75

VI

HH
ABSTRACT

An overview is given of grants awarded by the National Bureau of

Standards under the Special Foreign Currency Program (SFCP) or by the

U.S. -Yugoslav Joint Board. Each grant is identified by title,

principal investigator, institution in Yugoslavia, NBS monitor, and

the monitor's organizational unit within NBS. The work is then

described briefly under the three headings "Summary Description of

Project Goals," "Results and Implications to Date," and "List of

Publications that Resulted from the Project." To demonstrate the

relevance of such grants to the programs of NBS, the grant

descriptions are ordered by NBS institutes and divisions. The

significance and purpose of the NBS/SFCP grant programs are discussed

in the Foreword and the Introduction. The NBS monitors and the

program manager judge this grant program to have had a high benefit to

cost ratio frcm the viewpoint of NBS.

Key words: Binational research cooperation; international scientific

cooperation; physical science research administration; research

planning; scientific research abstracts; Special Foreign Currency

Program; Yugoslavia science and technology.

VII

NBS SPECIAL FOREIGN CURRENCY PROGRAM IN YUGOSLAVIA ] 973/77

1. INTRODUCTION

This Technical Note is intended to provide a review of the

scientific and technological grants program of the National Bureau of

Standards (NBS) conducted in Yugoslavia by use of Special Foreign

Currency Program (SFCP) funds. Such information is needed for any

value judgment, be it from the viewpoint of the disciplines, the

institutions or the technological plans of countries. Each grant

funded by the NBS/SFCP since the last similiar review (NBS Technical

Note 753) is described briefly in terms of its initial project goals,

its significant accomplishments, and its implications for science or

technology at the cooperating institutions of both countries.

The NBS Special Foreign Currency Program discussed in this report

can be traced to visits to Yugoslavia of two small NBS scientific

teams in September 1970 and October 1972. These teams accumulated

firsthand information about science and technology in Yugoslavia based

on discussions with scientists, engineers, educators, R&D

administrators, and governmental officials. Visits to more than two

dozen selected laboratories and institutes in eight cities including

Belgrade, Zagreb, Ljubljana, Sarajevo, and Zenica were completed in

two two-week periods. In parallel with proposals by Yugoslav

scientists through their institutions and committees in the Republics,

reconrnendations were made to the Director of the National Bureau of

Standards for funding projects in Yugoslavia under the Special Foreign
Currency Program based on the teams' evaluation of the projects in

accordance with established criteria, and the capabilities of those

submitting the proposals to undertake and successfully complete the

work.

The Program seen from the point of view of NBS can be said to be

of direct benefit to at least five major elements of the NBS mission.

Several of the projects are involved with measurement techniques not

yet exploited at NBS. Input for the National Standard Reference Data

System is provided in areas not yet being investigated at NBS. Many

NBS projects are currently involved with computer control of

experiments. Closely related is the project in Yugoslavia on

interactive control between experiments and computer. Finally/ some

of the Yugoslav projects are concerned with the development of

standards and standard reference materials, supplementing NBS work and

providing both new and better characterized standards.

The Yugoslav oriented reader should ask whether new and increased

capabilities have been brought to Yugoslavia by these projects and

whether the collaboration has been useful to institutional and

national goals. Questions should be asked: Have new competences been

built up and existing ones strengthened? Have scientific and

technological talents been diverted from the national goals of

Yugoslavia? Have neighboring fields been enriched in Yugoslavia by

cross-fertilization? Have applications in industry been sparked and

has the Program helped to develop a broadly based infrastructure of

science and technology in Yugoslavia?
Readers who are experts in the fields of investigation may ask

such questions as:

1. Were the projects in the fields familiar to you

well executed?

2. Did the senior investigators demonstrate exceptional

competence which could be of special service in the

future?

3. Did the projects contribute to the solution of problems

of known importance to science, technology, and

society?

4. Is there evidence that contact between US and Yugoslav

scientists was intellectually stimulating and helpful

in related work?

5. Does the program appear to have contributed to a

stimulating climate for scientific progroess and

technological innovation?

6. Did the program help to widen the horizons of scientists

towards application of their expertise to urgent national

needs?

7. Does this report suggest that bi-national programs of

this type should be developed for mutual benefit?

This list of questions is certainly not exhaustive nor are their

answers by any means obvious.

This report is addressed most particularly to scientifically

trained science administrators. He should remember, however, that the

financial support given to the NBS/SFCP has amounted to less than

$300,000 spread over all projects in the almost ten years. The

extreme modesty of these funds has been the principal constraint on

the program, but it must be acknowledged that institutions have in

most cases added from their own resources so that the true cost of the

research has been somewhat higher.
Several management details may be responsible for much of the

success of this program. First of all, the NBS monitor has been

strongly encouraged to communicate directly with the principal

investigator. Secondly, proper scheduling of visits by the NBS

monitors to Yugoslavia has broadened the basis of interaction. Thus,

the input to the NBS/SFCP from the NBS monitor can be based upon his

knowledge of the general Yugoslav scientific context of the particular

project which he is monitoring. To promote widespread knowledge at

NBS of Yugoslavian scientists and institutions, whenever it becomes

necessary, for scientific reasons, for an NBS monitor to visit his

project in Yugoslavia, he is urged to visit as many additional

scientific institutions and laboratories as possible. Such visits are

described in reports, on his return, which include his appraisal of

the scientific competences and the particular strengths of

individuals, laboratories, and institutions that he observed. In

addition to serving to broaden the outlook of the particular NBS

monitor, it increases the extent of the contacts between Yugoslav

scientists and the NBS staff, thereby enabling the Yugoslav scientist

to see NBS from the various points of view brought by the NBS

visitors. This increases the likelihood that Yugoslav scientists

involved in the program will, to a certain extent, insert an NBS point

of view in addition to their own, into goals set for their projects.

By careful planning of such NBS staff visits their cost has been kept

to a fraction of the project funds available. The trip reports by the

two NBS teams that visited Yugoslavia are recommended reading for NBS

staff visiting Yugoslavia in the future.

4

BSDH^K
The files of the program contain a growing number of examples of

collaborative work which has been of direct utility to either or both

sides. Such collabortive efforts are extremely important in today's

world. The unit for scientific research is seldom an individual

scientist, but rather a team. The complex and interdisciplinary

nature of modern scientific work makes use of self-contained, local

expertise of utility only as a component in collaborative efforts

which cross lines normally separating institutions, countries and

areas of research.

Some of the work reported here was completed as much or more than

two years ago. Nevertheless, it is believed that these reports should

be issued as a summary of the activities supported and encouraged by

this program. The editors would greatly appreciate receiving any

comments that the readers would care to make regarding any of the

individual projects or the overall program.

Identification of commercial products does not imply recommendation or endorsement by the National Bureau of Standards nor that the

product is necessarily the best available for the purpose.
HH vum
Project Title : DETERMINATION OF IMPURITY LEVELS IN ANALYTICAL

GRADE AND ULTRAPURE CHEMICALS BY ACTIVATION

ANALYSIS USING TRIGA REACTOR

Principal Investigator: Professor Dr. Lado Kosta

Institution: Jozef Stefan Institute, Ljubljana

NBS Monitor : Dr. P. D. LaFleur

NBS Institute or Center and Division : Institute for Materials Research

Analytical Chemistry Division

Summary Description of Project Goals

The goals of this project are the development of methods of trace

element analysis and certification of the content of important trace

elements in certain Standard Reference Materials. The analyses are

based on radioactive tracer and activation analysis (both slow and

fast neutrons) techniques, which permit the coverage of a wide

spectrum of materials and a large number of elements critical in many

applications—quality control of agricultural products and in the food

industry, the suitability of raw materials for particular purposes,

aspects of process control, and in the evaluation of import and export

products

The SRM's include some from the NBS series, particularly

biological materials and glasses, plus a new series which are being

prepared by NBS, IAEA, and SEV, which are likely to be specifically

recognized by organizations such as IUPAC. This new series includes

glasses, calcite, zinc, kaolin, magnesite, quartz, river sediments,

homogenized and freeze-dried tissues, and some basic foods such as

powdered human milk, and vegetables (i.e. spinach) . The methods
developed should also be important in implementing the new Yugoslav

Federal Law on Standardization and Quality Norms, which requires

certification of a wide range of materials used in agricultural, food,

chemical, metals, paper, and electronic industries.

Results and Implications to Date

The various methods of analysis and separation developed during

this project are shown by the titles of the publications listed in the

next section. Most of these methods have been applied by the authors

to assist in the characterization of various NBS SRM's, and all have

important potential for future characterization work.

There is an increasing emphasis in setting tolerance limits for

trace elements in a wide range of materials of commerce. This

requires reliable measurements, measurements which can successfully be

carried out in many laboratories if they have reliable SRM's for the

calibration of their analytical processes and devices . But very few

laboratories are capable of carrying out the absolute measurements

required to characterize these SRM's. NBS is one, JSI another. The

collaboration of these two laboratories has yielded significant

advantages to both, and to the larger analytical community which they

serve, by speeding the development of adequate absolute techniques

which have been successful both in extending the range to lower

concentrations and in overcoming difficult separation problems.

List of Publications that Resulted from the Project

1. V. Ravnik, M. Dermelj and L. Kosta, "A Highly Selective

Diethyldithiocarbamate Extraction System in Activation

Analysis of Copper, Indium, Manganese and Zinc,"

J. Radioanalytical Chem. , 20 pp 443-453 (1974).

8
2. A. R. Byrne and L. Kosta, "Simultaneous NeutronActivation Determination of Selenium and Mercury in

Biological Samples by Volatilization, "Talanta, Vol. 21,

pp 1083-1090 Pergamon Press (1974) .

3. A. R. Byrne, "Neutron Activation Analysis of Tin in

Biological Materials and Their Ash Using -^Sn and

125 Sn, " J. Radioanalytical Chemistry, Vol. 20

627 (1974)

4. A. R. Byrne and V. Ravnik, "Analysis of Arsenic in Glass

Standards by Neutron Activation Analysis," Radiochem.

Radioanal. Letters 20/2 pp 117-136 (1974).

5. A. R. Byrne and A. Vakselj, "Rapid Neutron Activation

Analysis of Arsenic in A Wide Range of Samples by Solvent

Extraction of the Iodide," Croatica Chemica Acta CCACAA 46

(3) pp 225-235 (1974)

6. V. Ravnik, M. Dermelj and L. Kosta, "Determination of

Some Trace Elements (Fe, Co, Cr, Zn, Cu, Mn, and In) in

Different Series of Standard Reference Samples by NeutronActivation Analysis," Mikrochimica Acta (Wien) pp 153-164

(1976) .

7. M. Dermelj, V. Ravnik and L. Kosta, "A Fast Isolation

and Determination of Cd in Some Fungi, Other Biological

Materials, Soil and Zn Metal by NAA, " Radiochem.

Radioanal. Letters 24(2) pp 91-102 (1976).

Project Title : ELECTROANALYTICAL DETERMINATION OF TRACE ELEMENTS

Principal Investigator : Dr. Marko Branica

Institution: Rudjer Boskovic Institute, Zagreb

NBS Monitor : Dr. John K. Taylor

NBS Institute or Center and Division : Institute for Materials Research

Analytical Chemistry Division

Summary Description of Project Goals

The aim of this work is to investigate and establish the

applicability/ advantages, and limitations of electroanalytical

procedures in comparison with other well known methods for the trace

analysis of natural waters.

Electroanalytical methods have often been used successfully in

the detection and determination of traces of heavy metals in aqueous

solutions. These rather simple and sensitive methods are specially

convenient for direct determination of trace metals in natural waters

(rivers, lakes, sea) and waste industrial waters. The present

research is directed to a better understanding of the methodology.

To achieve reliable and successful electroanalytical

determination of trace metals in natural waters, it is necessary to

investigate simultaneously:

(a) the development of very sensitive analytical techniques and

procedures, which enable direct determination at a con- centration level of 10 M or less

(b) the characterization of the species actually present in the

sample, and

(c) the study of chelation, hydrolization and other interactions

between metallic ions and inorganic and organic ligands

in natural aquatic systems.

11
In addition it is desirable to take into consideration the

possible changes in sample composition due to adsortpion and

interaction with container walls.

Results and Implications to Date

The results obtained were reviewed at the 7th IMR Symposium,

NBS/Gaithersburg (1) . Although anodic stripping methods have been

widely applied during the last ten years for determination of some

heavy metals in natural water systems, relatively little has been done

on this use in physico-chemical characterization and on determinations

of special importance for elucidation of respective biochemical cycles

and the fate of radioactive or industrial wastes. The experience in

application of electroanalytical techniques in the laboratory were

presented and discussed with regard to: determination of

concentrations of some metal ions; characterizatiins of the species

actually present; and study of chelation, hydrolization and other

interactions between metallic ions and organic ligands in natural

aquatic systems.

Anodic stripping voltammetry (ASV) with the rotating glassy

carbon electrode has been investigated and used for determination of

cadmium and lead, and the slowly dropping mercury electrode was used

for determination of zinc in the sea water samples from the North

Adriatic. The reproducibility of measurements, behaviour of

electrodes, the role of cell and storage bottle materials, and

sampling procedures were discussed.

12
The principle and the applicability in trace metals analysis of

differential stripping voltammetry (DSV) with two symmetrical rotating

glassy-carbon electrodes covered by a thin mercury film were studied

as a new development of electroanalytical methods (2)

A new method for characterization of the ionic state of a metal

at very low concentrations, based on voltammetric measurements has

been investigated. The formation of complexes of cadmium at a

concentration of 5 x 10~9 M with chloride in the solution of constant

ionic strength, y = 0.7 (NaCl + NaClO ) , and with thiocyanate, H =

2.0 (KNOo + KSCN) , as well as complexes of lead with chloride were

studied to illustrate the possible application of the method (5) .

In many natural waters and especially in polluted waters, the

presence of dissolved organic matter, which could act as a complexing

or chelating agent for metallic ions, can be expected. Surface active

substances (organic matter, detergents, oils), dissolved or

colloidally dispersed in natural water also can be adsorbed on the

electrode surface. These adsorption processes change the capacity

current and suppress (or even eliminate) the faradaic current, which

means that they strongly influence the electroanalytical results,

changing the sensitivity, potential and velocity of electrode

processes.

It is very probable that synthetic detergents represent the most

significant surface active compounds among various organic pollutants

entering natural waters. The polarographic method of discontinuously

changing potential, known as the Kalousek commutator technique, was

13
applied to the estimation of surface active substances in samples of

polluted seawater on the basis of the adsorption effects at the

mercury electrode.

Future research will study the stability of sea water samples

when stored under various conditions, with the objective of evaluating

the feasibility of using this material as an SRM for trace metals.

Electroanalytical determinations of trace elements in natural waters

are influenced by many different factors, as are results obtained by

any other well known methods. Therefore, the proposed research

involves many complex and mutually interacting investigations, and

merits a larger allocation of staff and funds.

List of Publications which Resulted from the Project

1. M. Branica, L. Sipos, S. Bubic and S. Kbzar, "Electroanalytical

Determination and Characterization of Some Heavy Metals in

Seawater," 7th Materials Research Symposium, National Bureau

of Standards, Gaithersburg, Maryland, USA, October 7-11, 1974.

NBS Special Publication 422, 1977 "Accuracy in Trace Analysis:

Sampling, Sample Handling, Analysis," Vol. II, pp 917-928.

2. L. Sipos, I. Kontusic and M. Branica, "Differential Stripping

Voltammetry with Two Rotating Glasy-Carbon Electrodes ,

Meeting of Chemists of Croatia 1975, Zagreb, February 12-14,

1975.

3. S. Kozar, L. Sipos and M. Branica, "Determination of Traces

of Heavy Metals by Differential Stripping Voltammetry,"

Meeting of Chemists of Croatia 1975, Zagreb, February 12-14,

1975.

4. Z. Kozarac, B. Cosovic and M. Branica, "Estimation of

Surfactant Activity of Polluted Seawater by Kalousek Commutator

Technique," J. Electroanal. Chem. 64, pp 75-83 (1976).

5. M. Branica, D. M. Novak and S. Bubic, "Application of

Anodic Stripping Voltammetry to Determination of the State

of Complexation of Traces of Metal Ions at low Concentrations Levels," submitted for publication in Croatia Chem.

Acta.

14
Project Title : : DEVELOPMENT AND APPLICATION OF ULTRASENSITIVE MAGNETIC

RESONANCE METHODS

Principal Investigator : Professor R. Blinc

Institution : Jozef Stefan Institute, University of Ljubljana,

Ljubljana

NBS Monitor : Dr. D. H. Reneker

NBS Institute or Center and Division: Institute for Materials Research

Polymers Division

Summary Description of Proj ect Goals

The purpose of this project is the development of new nuclearnuclear double resonance methods which allow a simple measurement of

the NMR and NQR spectra of nuclei which are too weak to be detected by

conventional magnetic resonance techniques as well as the development

of new multipulse NMR spin-echo methods for the measurements of the

translational self diffusion in svstems where normal NMR spin-echo

methods cannot be applied because spin-spin relaxation times are too

short. The multipulse NMR spin echo methods are being used to measure

the seqmental diffusion of polyethylene molecules in the melt , and to

characterize the diffusion of small molecules , particularly butane in

solid polyethylene. The advantages of the NMR methods for

characterizing diffusion processes promise to be of great value in

relation to NBS programs concerned with the prediction of migration of

additives from polymers, particularly those that create health hazards

by migrating from packaging materials into foodstuffs.

15
Results and Implications to Date

The following results have been obtained so far:

1. A new nuclear-nuclear double resonance technique (1) has been

developed which allows the measurement of the pure NQR spectra of

integer spin nuclei (like 14 N and 2

H) by double resonance with half

integer spin nuclei like protons in cases where spin quenching

prevented the use of classical nuclear-nuclear double resonance

techniques. The new technique is based on the solid effect, i.e., on

strong r.f . magnetic field induced coupling between spin systems. It

has been applied in several investigations, including the first

measurement of the nuclear quadruple resonance spectra of ^N in

polypeptides (3)

.

2. A new multipulse NMR spin-echo technique (4) has been

developed which allows for self-diffusion measurements in systems

where this was not possible previously because the spin-spin

relaxation times are too short. The new technique extends the range

of the NMR determination of selfdiffusion coefficients from liquids

and gases to adsorbed molecules, biological polymers, liquid crystals,

and in favorable cases even crystalline solids. The pulse sequence

o used consists of: (i) A Waugh-type multiple 90 rf pulse sequence

removing dipolar interactions: - fy- (t-^ -2t-^ -t-E- ) ; (ii) a pulsed,

linear, magnetic-field-gradient sequence placed between the rf pulses

at such intervals that its effect is not averaged out by (i) ; (iii) a

o slow, refocusing, Carr-Purcell train of 180 rf pulses. Steps (ii)

and (iii) are similar to the technique used by Tanner, whereas step

16
(i) is new and essential for the observation of spin echoes which

make the measurement of the self-diffusion coefficients feasible.

This technique was used to measure the diffusion coefficient of butane

in polyethylene as a function of pressure. The results show that the

method provides new insight into the diffusion process since by

measurinq diffusion over small distances it avoids problems of

interpretation which arise because spherulite boundaries are difficult

to characterize. The NMR methods also measure the diffusion

coefficient at a particular concentration of butane instead of

averaging over a wide concentration ranae as is necessarily the case

with alternative methods. Other advantaqes of the NMR method are that

it provides relaxation time information and it may be used in a

straight forward way to measure anistropy in the diffusion coefficient

of certain kinds of oriented polvmer samples. It appears probable

that these measurements will have direct beneficial impact on NBS

proqrams concerned with the prediction of durability and safety of

plastics where migration of small molecule additives are important, as

is frequently the case.

The new NMR methods were also shown to be useful for measuring

the self diffusion of molten polymers. This information, not

previously obtainable by straightforward experiments, bears on polymer

mixing and flow problems frequently encountered in the processing of

polymers.

17
Still another application was the study of the self-diffusion of

adsorbed water in biological polymers like oriented Na-DNA where a

significant anisotropy of the self-diffusion coefficient was detected

as well as the presence of restricted diffusion due to the fibrous

structure of the sample. The typical fibre diameter necessary to

explain the restriction of the diffusion was found to be about one

micrometer. It should be mentioned that this research is part of a

long range research program of the Jozef Stefan Institute. About half

of its effort has been funded by Institute sources and the Slovenian

Research Community.

List of Publications Resulting from Project

1. J. Seliger, R. Blinc, M. Mali, R. Osredkar and A. Prelesnik,

"Nuclear Magnetic Double Resonance Eased on Strong rf MagneticField-Induced Coupling Between Spin Systems," Phys. Rev. B 11,

27 (1975) .

2. R. Blinc, M. Mali, R. Osredkar and J. Seliger, "Nitrogen and

Chlorine NQR in Paraelectric and Ferroelectric Tris-Sarcosine

Calcium Chloride," Journal of Chem. Phys. 63, 35 (1975).

3. R. Blinc, M. Mali, R. Osredkar, J. Seliger and L. Ehrenberg,

"Nl^ Quadrupole Resonance in Polyglycine , " Chem. Phys.

Letters 28, 158 (1974).

4. R. Blinc, M. Burgar, M. Luzar, J. Pirs, I. Zupancic and

S. Zumer, "Anistropy of Self-Diffusion in the Smectic A and

Smectic C Phases," Phys. Rev. Letters 33, 1192 (1974).

5. R. Blinc, J. Seliger, R. Osredkar and M. Mali, "0--^ Quadruple

Resonance Study of the Ferroelectric Phase Transitions in

KHoP04 ," Phys. Letters 47A, 131 (1974).

6. J. Seliger, R. Osredkar, M. Mali and R. Blinc, "N 1^ Quadrupole

Resonance of Some Liquid Crystalline Compounds in the Solid,"

Journal of Chem. Phys. 65, 2887 (1976).

18
7. R. Blinc, Proceedings of the Enrico Fermi International

Summer School on Local Properties at Phase Transitions, Varenna,

Italy, 1973, 165 (1975)

8. I. Zupancic, G. Lahajnar, V. Rutar, Lj. Miljkovic and

A. Rupprecht, paper presented at the XlXth Congress Ampere,

Heidelberg 1976, to be published in the proceedings of the

Congress

9. I. Zupancic, G. Lahajnar, R. Blinc, D.H. Reneker and

A. Peterlin, "NMR Study of Diffusion of Butane in Linear

Polyethylene," to be published, J. Polymer Sci. (1978).

10. I. Zupancic, G. Lahajnar, R. Blinc, D. H. Reneker and

A. Peterlin, "NMR Line Shape, Relaxation, and Self Diffusion

of Polyethylene in the Melt," in draft.

19

Project Title : ELECTROCHEMICAL STUDY OF METAL ICN-LIGAND INTERACTION

IN NONACQUEOUS SOLUTIONS BY INVESTIGATION OF ELECTROCHEMICAL PROPERTY OF LIGAND

Principal Investigator : Professor Ivan Piljac

Institution : Institute of Inorganic Chemistry, Faculty of Technology,

University of Zagreb

NBS Monitor : Dr. John K. Taylor

NBS Institute or Center and Division : Institute for Materials Research

Analytical Chemistry Division

Summary Description of Project Goals

This research was undertaken for the purpose of finding a

correlation between the strength of metal-ion-ligand interactions and

the changes in electrochemical properties of ligands.

Investigations of hydroxy-quinone and of their conjugate base in

non-aqueous media was performed by polarography and other

electrochemical methods. Electrochemical measurements were combined

with spectroscopic ones using the thin-layer, optically transparent

electrochemical cell.

This is a new approach to the problem of studying metal ion and

organic ligand interactions with the effect of coordination reactions

of the molecular orbitals in the ligand which can be related to the

electrochemical properties (e.g. half-wave potential) . In addition,

important information can be obtained concerning the ability of the

ligand to donate electrons to metal ions in the process of forming

chemical bonds, and further, to identify the type of molecular species

resulting from such reactions. The kinds of information and chemical

data which can be expected to be generated in this project should be

of fundamental interest in several areas of electrochemical analysis

21
and of iirportance to scientists working in coordination chemistry,

especially those engaged in chemical problems in such fields as

coordination polymers and biomedical research involving metal ionligand interactions.

Results and Implications to Date

The work completed to date represents the first phase of the

electrochemical and spectroelectrochemical studies of metal ion -

ligand interactions based on an investigation of the electrochemical

property of ligand.

1. By application of DC polarography and cyclic voltametry on the

l-hydroxy-9 10-anthraquinone in DMF solutions in the presence

of Li ion, the complexity of the electrode reduction of HOAQ to

radical ion was demonstrated. The study established that the

following factors must be considered in establishing exact

quantitative relationships between the electrochemical magnitudes

and the strength of metal ion - ligand interactions:

(a) ihe association of the metal ion with the electrode

reaction product. This factor shifts the reduction

potential in the positive direction. It is important

to analyze the kinetic aspect of this interaction,

especially with respect to the speed of reaching

equilibrium.

(b) The association of the metal ion with the unreacted

organic molecules by forming a covalent bond.

This factor is especially important with aromatics

carrying electron-donor groups or atoms and causes a shift of the reduction potential in the negative

direction.

(c) The direct participation in electrochemical reaction

of the complex species formed by association of

organic molecules with metal ion. This process may

be of considerable importance, together with the

free electroactive species reduction, especially

when more than one electroactive group resides on

the organic molecule. The complex species will be

reduced at a more positive potential than that of

the free depolarizer. This factor is likely to be

manifested as a change in DC polargraphic reversibility.

22
2.

Surely, all these factors cannot be adequately

studied by using only electrochemical techniques.

The necessity of taking recourse to other physiochemical methods, particularly to methods based on

spectrophotometric and especially simultaneous

spectroelectrochemical techniques, is quite obvious.

In our own work , the optically transparent thinlayer cell proved advantageous in providing a

satisfactory explanation of results observed, but

not explained, by other techniques.

Mathematical models were constructed by deriving a theoretical

expression from the Nernst equation for different types of

metal ion - ligand interactions, and on these models a

computer simulation of polarographic waves, as well as calculation of "theoretical 1

* half-wave shifts was made.

3. Analog circuitry for electrochemical measurements based on

operational amplifiers was manufactured and its DC polarographic part was connected on-line to a digital computer.

Appropriate programs for data collection and analysis were

worked out.

4. The use of optically-transparent thin-layer (OTTL)

cells for a study of metal ion - ligand interaction with

electrode reaction products was demonstrated and an

appropriate OTTL cell was constructed.

List of Publications that Resulted from the Project

1. I. Piljac, M. Tkalcec and B. Grabaric, "Use of Optically

Transparent Thin-Layer Cells for Determination of

Composition and Stability Constants of Metal Ion Complexes

with Electrode Reaction Products," Anal. Chem. 47, 1369

(1975).

23

Project Title : MASS SPECTROMETRIC STUDIES OF HIGH TEMPERATURE

EQUILIBRIA

Principal Investigator : Dr. Kiro F. Zrnbov

Institution : Boris Kidric Institute of Nuclear Sciences, Vinca

NBS Monitor : Dr. J. W. Hastie

NBS Institute or Center and Division : Institute for Materials Research

Inorganic Materials Division

Summary Description of Project Goals

A Knudsen-effusion-mass spectrometric technique will be used to

monitor chemical equilibria at high temperatures and low pressures.

The bond dissociation energies of participating molecules will be

determined

An electron monochromator will be developed and utilized as an

extension of existing characterization techniques for high temperature

vapors . This will allow more accurate determination of molecular

ionization and dissociation energies than existing techniques which

utilize non-monochromatic low-resolution electron sources. Such a

device should prove useful in the mass spectrometric detection of

radical species, e.g., in flame studies.

Results and Implications to Date

1. A Knudsen effusion cell for the study of high temperature

equilibria has been constructed and attached to a mass spectrometer

which has been designed previously in this laboratory.

2. The mass spectrometer-Knudsen effusion apparatus has

been employed to study the following high temperature equilibria:

25

^m
Te0

2

(g) + Te(g) = 2 TeO(g)

Te0 2

(g) + Pb(g) = TeO(g) + PbO(g)

Te0 2

(g) + 2Pb(g) = Te(g) + 2PbO(g)

TeO(g) + PbTe(g) = Te 2

(g) + PbO(g)

Fran the measured enthalpies and known heats of formation

of PbO and PbTe molecules, the heats of atomization of TeO(g)

and Te02

(g) molecules have been determined by isomolecular

exchange reactions

3. The composition of the gas phase above the reaction

mixture CuCl + Si in a copper Knudsen cell has been investigated,

From the mass spectra and appearance potentials of the ions the

following parent molecules have been identified at temperatures

near 200°C: SiCL . SiCl^, Si- CI , Si CI and S:L0C1 . The

ionization potentials of these molecules have been measured and

the reaction

SiCl

2

(g) + SiCl

4

(g) = S^ClgCg)

has been studied over a range of temperatures (160 - 200 C)

.

Equilibrium constants for this reaction have been measured, and

the reaction enthalpy determined by the second-law method. The

data were used to obtain the Si-Si bond dissociation energy in

the silicon hexachloride molecule.

4. Isomolecular exchange reactions involving gaseous

atoms and oxides of lead and antimony at high temperatures have

bean studied.

Preliminary results have been obtained on the equilibrium

constants and enthalpy change for the reaction -

26
Pb(g) + SbO(g) = PbO(g) + Sb(g);

Gaseous PbO has been detected for the first time at

temperatures of 800 -950 K and its ionization potential measured

by semilog and extrapolated voltage difference methods. The isomolecular exchange reaction -

PbO (g) + Pb(g) = 2 PbO(g)

was studied and the dissociation energy of the PbO~ molecule

was determined by the third law method.

These thermochemical studies are of direct interest to NBS in

relation to its efforts to model the flame inhibiting effects of

antimony.

5. A trochoidal electron monochromator (TEM) has been designed

and attached to the ionization chamber of a Nier-type ion source of

the mass spectrometer. The initial design has been modified in order

to shield the electron beam from stray magnetic fields. The electron

stopping curves have been measured by the retarding potential method,

and the energy spread of the electron beam has been measured at both

the entrance and exit of the monochromator. Beams with an energy

spread of 40 mV were obtained, but their intensity was only of the

order of 10 amps

The trochoidal electron monochromator has been used to study

formation of negative ions by electron impact of SF and SO . The

6 2

studies of SO gave interesting results . Besides the expected stable

negative ions, ions were also detected which are analogous to

27
metastable ions in the positive ion spectra. The origin of these ions

is still uncertain, and it is assumed that they are formed by

decomposition of some primary ions of masses higher than the mass of

the parent molecular ion. This indicates the existence of heavy ions

formed either by ion-molecular reactions or by electron attachment to

the dimer (S0«) ~ molecule. Further work is under way to elucidate the

origin of these "metastable" ions.

This monochromator is of potential interest to NBS (and others)

for molecular studies in high temperature and combustion chemistry.

Further work is needed to demonstrate its utility in molecular beam

systems.

6. A large number of stable inorganic molecules have been

detected in high temperature vapors , but precise measurements of their

ionization potentials are still lacking. The surface ionization

method offers a possibility for measuring the ionization potentials

and it has been applied in many cases, but only for atoms.

It was therefore of interest to investigate the possibility of

applying the method to determine the ionization potentials of gaseous

inorganic molecules.

LaS and ThO molecules were chosen for initial study. A surface

ionization ion source was built in which the vapor of the sample was

produced by heating in a tantalum oven and a heated metal ribbon

served as the ionizing surface. The ions formed on the surface were

analyzed by a conventional magnetic mass spectrometer equipped with an

electron multiplier for ion detection.

28
Ions La+ , LaS + and LaO+ were detected when an LaS sample was

heated in the Ta-oven and the vapors ionized on Ta and Re surfaces at

temperatures between 1800 and 2500 K. Linear plots of In I (LaS) vs

1/T were obtained in the temperature range 2200 to 2500 K. From the

slope of this plot, the ionization potential of the LaS molecule was

calculated to be 6.5 +0.2 eV.

When ThO vapors interact with a heated Re surface, ions Th and

ThO are produced. The plot In I (Th+ ) vs 1/T is linear in the

temperature range 2200 - 2600 K with an activation energy of 9.8 +0.2

eV. This value can be explained as a sum of the dissociation energy

of ThO and ionization potential of Th reduced by the work function of

Re:

-E = W_ -[I.P.(Th) + D(ThO) ] . a Re

Thus, the unusually high activation energy for the production of Th

ions by surface ionization of ThO molecules offers a possibility of

determining either the ionization potential of Th or D(Th-O)

Both ionization potentials and bond dissociation energies are

needed in the interpretation of mass spectra and chemical processeses

for the molecular beam sampling of combustion systems.

List of Publications that Resulted from the Project

1. K.F. Zrnbov, M. Miletic and M. Hofman, "Thermochemistry of

SiCl2 and Si^Clg Molecules and Bond Dissociation Energy

of Si-Si in Si2Clg, " Third Yugoslav Congress of Pure and

Applied Chemistry, Ljubljana, June 1972.

29
2. R. Maksic, M. Miletic, A. Stamatovic and K.F. Zmbov,

"Metastable Transitions in Negative Ion Spectra of SOp,"

8th International Conf . Electron Atom Collisions, Belgrade,

p. 463 (1973) .

3. R. Maksic, M. Miletic, A. Stamatovic and K. F. Zmbov,

"Negative Ions in SO2, 1 ' 18th Annual Meeting of Serbian

Chemists, Novi Sad (1974).

4. M. Miletic, A. Stamatovic, R. Maksic and K.F. Zmbov,

"Modification of an Ion Source for Improvement of the

Electron Energy Resolution," Adv. Mass Spectrometry 6,

523 (1974)

.

5. N. Djuric-Pregar, A. Stamatovic, M. Miletic and R. Maksic,

"Mass Spectrometric Study of Negative Ion Formation in SCU/"

Proc. 7th Symp. Phys. Ionized Gases 7, 55 (1974).

6. A. Neubert and K. F. Zmbov, "Mass Spectrometric Determination

of the Dissociation of ThO Molecule," High Temp. Sci., 6, 303

(1974) .

7. A. Stamatovic and M. Miletic, "Metastable Ions from SiCl*,"

Proc. 8th Symp. Phys. Ionized Gases 8, 105 (1976)

.

8. K. F. Zmbov and M. Miletic, "Mass Spectrometric Determination

of the Dissociation Energy of Pb02 and Ionization Potentials

of PbO and PbC^ Molecules," Adv. Mass Spectrom. 7 (1976)

.

9. H.R. Ihle, C.H. Wu, M. Miletic and K. F. Zmbov, "Mass

Spectrometric Study of Vapor Species in Si-Li and Si-Cl

System," Adv. Mass Spectrometry 7 (1976).

30
Project Title ; X-RAY DIFFRACTION AND ELECTROMICROSCOPIC STUDIES ON

ALUMINUM AND ON THE METASTABLE PHASES OF ALUMINUM BASE

ALLOYS, OBTAINED BY RAPID QUENCHING FROM THE MELT

Principal Investigator ; Professor Dr. A. Bonefacic

Institution ; Institute of Physics of the University of Zagreb, Zagreb

NBS Monitor ; Dr. Richard P. Reed

NBS Institute or Center and Division ; Institute for Basic Standards

Cryogenic Division

Summary Description of Project Goals

By rapid quenching from the melt, supersaturated solid solutions,

new metastable phases and amorphous phases unobtainable by classical

quenching procedures may be obtained.* Quenching from the liquid

state results in a high concentration of defects and small grain size

formation, so that pure materials splatcooled from the melt differ in

certain properties from the reerystallized samples.

The principal purposes of the project are:

1. Examination of the structural properties of aluminum-based

supersaturated solid solutions directly after quenching and of the

diffraction, electron-microscopy and hardness measurements.

2. Comparison of the structural and mechanical properties of

alloys quenched from the liquid state with those of alloys quenched

from the solid.

3. Investigation of pure aluminum quenched from the liquid.

4. Study of the applicability of X-ray cameras for quantitative

scattering measurements, with respect to the error introduced by the

distortion of the true scattering curves. Errors due to different

forms and sizes of aperture and the collimation error due to the width

of the incident beam and its divergence are to be considered.

* Pol Duwez, R. H. Willens and W. Klement Jr., J. Appl. Physics 31,

1136 (1960)

Pol Duwez, R. H. Willens and W. Klement, Jr., Ibid, p. 1137.

Pol Duwez and R. H. Willens, Trans. Metallurgical See. of AIME,

227, 362-365 (April 1963)

31
Results and Implications to Date

The project was signed by the U . S

. -Yugoslav Joint Board on

Scientific and Technological Cooperation on 13 May 1974, but work

related to this investigation began earlier and funds from other

sources were intermixed with those from this project. The present

project is part of a long-term research program on metastable metallic

alloys of the Institute of Physics of Zagreb University. The results

obtained during the recent period are described in the same order as

listed in the summary description of the project goals.

1. Aluminium-based supersaturated solid solutions Al-Ni,

Al-Sn and Al-Pt were studied.

The solid solubility of Pt in Al was extended from to 2 atomic

percent by the "two-piston" quenching technique. The stability of the

Al-Pt solid solutions during annealing was examined. During the

decomposition an intermediate metastable phase was detected, and

its unit cell constants were determined (2)

.

The intensity of scattering of monochromatic X-rays at small

angles from Al-3.6 at.% Ni and Al-0.26 at.% Sn solid solutions

was studied in order to determine if the solutes are dispersed.

Electron-microscopic examinations were also carried out. Both alloys

were obtained by rapid quenching from the melt to obtain the optimum

dissolution. No perfectly homogeneous solid solutions were obtained,

but agglomerations of solute atoms wsre detected. The evolution of

clusters during annealing was examined and their influence on microhardness and microstrain properties evaluated (7)

.

Fourier analysis of the shape of diffraction peaks showed

that in splat-quenched Al-Sn and Al-Ni solid solutions the major

sources of peak broadening is microstrains which increase with

increasing concentration of solute atoms (3)

.

2. The age hardening of aluminium-4 . 5 at.% silver alloys

quenched from the liquid state (LQ) indicates that the decomposition processes in rapidly cooled specimens differ from those in

conventionally quenched ones. Guinier-Preston (G.P.) zones wsre

present in the as-quenched state and were about half the size of

those in the specimens quenched from the equilibrium solid

solution state (SQ) . The precipitates nucleated, grew, and

disappeared more readily in the liquid-quenched than in the solid32
state-quenched specimens, causing an overlap of cold and warm

hardening stages and an earlier attainment of maximum hardness

with aging (1)

G.P. zones which form in certain solid solutions may be

represented by several models of particles of non-uniform electron

density. Small-angle X-ray scattering curves for various models

of spherically symmetric particles have been calculated. The

scattering functions for particles having a Gaussian and a cosine distribution of electron density, and for dilute systems

of such particles of various degree of polydispersity were

calculated and compared with the scattering of spheres of

uniform electron density, considering the statistics both of

mass and of the number of particles (4)

Other models being studied are:

(a) the gradual transition of electron density is

restricted to the outer shell of the particle;

(b) the electron-density transition is partly gradual

and partly sharp; and

(c) the particle consists of two parts of uniform

electron density which may be of opposite sign.

The latter model includes the Guinier-Walker model which has been

proposed to represent the G.P. zones in aluminum-silver alloys.

In the large-angle region all scattering curves oscillate

around a curve which runs proportionally to (20) _n/ where n

is an even number. Whenever the transition of electron

density is gradual , the exponent n exceeds 4 . However , even

if a small abrupt drop of electron density is present, the

value of n becomes 4 (Porod ' s Law) . In the small-angle region

the scattering curves are approximately of the Gaussian form,

except for some models of particles which have an excess of

electrons in the inner part and a deficit in the outer part

(and vice versa) with respect to the surrounding medium. For

these particles, some parameters characterizing the scattering

curves were calculated to facilitate the evaluation of the

experimental scattering curves.

An attempt was made to show whether the early stage of

decomposition of the quenched Al-Ag alloy could be explained by

the linear spinodal (LS) theory. Only the initial time dependence

of small-angle-scattering spectra recorded in the lower-angular

range explored was in rather good agreement with the LS theory.

The interdiffusion coefficients were determined from these

data. The value for the SQ specimen was one order of magnitude

greater than the corresponding value for the LQ specimen, both

annealed at 140°C. For lower temperatures, this difference

33
became smaller.

3. Measurements of the broadening of X-ray diffraction

peaks ware made for splat-cooled pure aluminum samples (3)

.

Using the Warren-Averbach profile analysis method, it was found

that the major source of broadening is strain.

The residual strains calculated from the dislocation density and

measured with an electron microscope were of the same order of

magnitude as that obtained by the line-broadening measurements

(10 ~4 ) . Microstrains may appear as a consequence of a large

temperature gradient during quenching. No preferred orientations

of crystallites were observed in the quenched samples. The

deformation fault probability determined by the peak-shift method

was very small (0.004) . No faulting in splat-cooled aluminum

samples could be detected by an electron microscopic examination.

4. The error introduced by distortion of the true X-ray

scattering curves as measured with the Levelut-Guinier camera

was considered. The distortion of different types of curves,

representing different scattering systems, was found by calculation, and the character and the amount of distortion evaluated (5)

.

The study of the distortions of scattering curves which

emerged when applying convergent and divergent incident beams

showed that the distortion of the Gaussian curves is greater in

the case of the convergent beam. The presence of s~^ dependence

in the tail of the scattering curve (Pored' s Law) was more clearly

revealed in the case of the convergent beam (6)

.

To summarize, the principal results of the project have been:

A variety of super-saturated solid solutions and new metastable

phases, unobtainable by classical procedures, were obtained. Comparative studies of their mechanical and structural properties have been

made.

Special efforts were made to correlate the microhardness,

X-ray small-angle scattering intensity, and X-ray peak-broadening

microstrain measurements, to indicate solute-atom clustering

in the series of new solid solutions.

Theoretical and experimental substantiation was made of the

small-angle scattering X-ray technique to identify solute atom

34
clustering

Electron-microscopic examinations ware used to study the

evolution of clusters during ageing.

The techniques of alloy characterization used in this project

may prove of great utility in further studies of stress-corrosion,

metallic glasses, and in alloy development.

By systematic and careful measurements on judiciously chosen

series of new splat-cooled alloys, important regularities and laws

governing the general behavior of alloys may be clarified.

List of Publications that Resulted from the Project

1. K. Kranjc and M. Stubicar, "X-ray Diffraction Study of Decomposition in Aluminium-Silver Alloys Quenched from the Melt," Met.

Trans. 4, 2631 (1973).

2. A. M. Tonejc and A. Bonefacic, "Nonequilibration Phases in Al-rich

Al-Pt Alloys, Mat. Sci. 9, 523 (1974).

3. A. Kirin and A. Bonefacic, "X-ray Line Broadening Study of Splat

Cooled Aluminium and Aluminium-tin and Aluminium Nickel Solid

Solutions," J. Phys. F: Metal Phys. 4, 1608 (1974).

4. K. Kranjc, "Small-Angle X-ray Scattering from Spherical Particles

of Non-uniform Electron Density," J. Appl. Cryst. 7, 211-218

(1974) .

5. K. Kranjc and A. Bonefacic, "Distortion of X-ray Small Angle

Scattering Curves Measured by a Levelut-Guinier Camera,"

J. Appl. Cryst. 7, 259 (1974).

6. K. Kranjc, "Distortion of X-ray Small-Angle Scattering Curves

Measured by a Levelut-Guinier Camera when the Primary Beam

Converges at a Point on the Counter," J. Appl. Cryst. 7, 498

(1974)

7. A. Bonefacic, M. Kerenovic, A. Kirin and D. Kunstelj,

"Segregation of Solutes in Al-Ni and Al-Sn Alloys," J. Mat. Sci.

10, 243 (1975).

35
E
Project Title; STARK BROADENING OF SPECTRAL LINES IN PLASMAS

Principal Investigator ; Dr. N. Konjevic

Institution ; Institute of Physics, Belgrade

NBS Monitor : Dr. W. L. Wiese

NBS Institute or Center and Division: Institute for Basic Standards

Optical Physics Division

Summary Description of Project Goals

This project covers a study of the Stark broadening and shift of

prominent lines of some singly, doubly and triply ionized atoms in

plasmas. The experimental results are compared with semiclassical

calculations based on various theoretical approximations.

The principal goal of this work is to supply new experimental

Stark broadening data for spectral lines of ionized atoms and to test

the various theoretical approaches for line width calculations. A

part of the work is devoted to the search for the systematic trends of

the Stark line widths within an element and within a group of

elements. Critical evaluations of existing experimental Stark

broadening data are also carried out.

Results and Implications to Date

Work in the last three years was concentrated on the following

tasks:

1. obtaining new Stark broadening data for lines of

elements for which measurements did not exist and

comparing them with existing theories

2. finding possible regularities of Stark broadened line

widths within an element and within a group of

elements, and

37
3. critical evaluation of existing Stark broadening

data

The last two parts of the Project were carried out in collaboration

with scientists from the National Bureau of Standards.

1. During the course of this work a number of singly, doubly

and triply ionized atoms were investigated as given in Table 1.

Table 1

Element Ionization State Number of Lines Investigated

2

9

4

21

6

5

2

15

5

2

4

2

5

Beryllium Be II

Nitrogen N II

N III

Oxygen II

III

Fluorine F II

Magnesium Mgll

Chlorine CI III

Argon Ar III

* Ar IV

Calcium Ca II

Strontium Sr II

Barium Ba II

38
A low pressure pulsed arc was used as a light source in these

experiments. The electron density was measured by laser interformetry

while electron temperatures were determined from the Boltzmann plots

of relative intensities of spectral lines. Electron densities were

typically around 5x10 *' cm~3 and temperatures in the range 22000-

26000 K.

Results for singly ionized lines of Be II, Ca II and FII agree

within the limits of experimental error with semiclassical calculations by Griem. In the case of F II, in addition, calculations of

the line widths have been performed according to the theory of

2 Baranger where hyperbolic perturber-path trajectories were used.

Theoretical results were also obtained combing Baranger' s approach

with GBK0 straight pertuber-path approximations for higher perturber

3 4 velocities. '

The agreement between the F II experiment and our semiclassical

calculations for singly ionized fluorine lines is good while the

results based on Baranger' s theoretical approach are systematically

higher. It follows from this comparison that Baranger 's perturberpath approximation (hyperbolic trajectories) is not adequate for

singly ionized atoms.

However, for the doubly and triply ionized atoms Ar III, Ar IV

and CI III the experiments agree best with theoretical results based

only on hyperbolic perturber-path trajectories while the results of

other theoretical approximations are systematically lower. This

suggests that the approach of Baranger is much better for higher

ionization stages than one would expect on the basis of comparison

39
with results for singly ionized atoms. This conclusion may be of seme

practical importance since Baranger's approach offers by far the

simplest method to evaluate line widths.

2. Stark broadening theory predicts regularities and systematic

trends for the Stark widths of isolated neutral atom and ion lines on

the basis of aspects of plasma as well as atomic physics. The

systematic behaviour of Stark widths with regard to plasma parameters

has been proven in a number, of experiments. However it is still a

largely unsettled question what regularities should be exhibited in

the width data as a consequence of atomic physics factors contained in

the line width expression.

On the basis of the present Stark broadening theory one would

expect:

I. Some similarities within a given spectrum:

a. The line widths of all lines in a multiplet should be

practically identical.

b. The width of all lines in a supermultiplet should be

approximately equal, and

c. Groups of supermultiplets having the same parent term in

a transition array should possess Stark widths of about

the same size.

II. Regularities within homologous atoms, and

III .Regularities within isoelectronic sequences.

Unfortunately a fairly large number of reliable experimental data

are needed in order to check theoretical predictions of the systematic

trends. The whole work in this field is in an early stage but the

first results are very encouraging. As an example, Table 2 gives our

results for the line widths of resonance lines of alkaline earth

40
atoms (homologous atoms) . From the table one can readily notice a

systematic increase of the line width with increase in atomic number

(and with decrease of ionization potential) .

-

Table 2

o Ion Transition Stark halfwidths (A)

Be II 2s*cS - 2pT> 0.05

Mg II 3s

2

S - 3P

2

? 0.08

Ca II 4s

2

S - ApV 0.20

Sr II 5s

2

S

Ba II 6s 2

S

- SpV 0.23

- epV 0.25

3. Within the scope of our work on the Stark broadening of

atomic lines in plasmas an attempt was made to evaluate critically all

existing experimental data on the Stark broadening of nonhydrogenic

spectral lines of neutral and ionized atomic species. The relevant

literature compiled by the NBS Data Center on Atomic Line Shapes and

Shifts was therefore critically evaluated and 68 papers dealing with

neutral and 54 with ionized atoms were selected. The experimental

data were then arranged according to the spectra and elements

presented in alphabetical order. The accuracy of the experimental

data was estimated on the basis of guidelines developed in the

reviews, and comparisons with theoretical results were made whenever

possible (6,7)

41
As a result of this work two review papers are now in print. To

our knowledge these two reviews represent the first attempt to

assemble and evaluate crtically the experimental material on the Stark

broadening parameters of isolated lines.

References:

1. H.R. Griem, Spectral Line Boradening by Plasmas

Academic Press , New York (1974) .

2. M. Baranger, Atomic and Molecular Processes edited

by D.R. Bates, Academic Press Inc., New York (1962)

.

3. J. Cooper and G.K. Oertel, Phys. Rev. Let. 18, 985

(1967) .

4. J. Cooper and G.K. Oertel, Phys. Rev. 180, 286 (1969).

List of Publications that Resulted from the Project

1. D. Hadziomerspahic, M. Platisa, N. Konjevic and M. Popovic,

"Stark Broadening and Shift of Some Isolated Spectral Lines

of Singly Ionized Alkaline Earth Metals," Z. Phys. 262, 169

(1973) .

'

2. M. Platisa, M. Popovic, M. Dimitrijevic and N. Konjevic,

"Stark Broadening of AIII and AIV Lines," z. Naturforsch.

30a, 212 (1975).

3. M. V. Popovic, M. Platisa and N. Konjevic, "Stark Broadening

of Nil and NIII Lines" Astron. Astrophys. 41, 463 (1975).

4. M. Platisa, M. V. Popovic and N. Konjevic, "Stark Broadening

of Oil and OIII Lines," Astron. Astrophys. 45, 325 (1975).

5. M. Platisa, M. Dimitrijevic, M. V. Popovic and N. Konjevic,

"Stark Broadening of FII and CIII Lines," in press. (To be

published in Astron. Astrophys.)

6. N. Konjevic and J. R. Roberts, "A Critical Review of the Stark

Widths and Shifts of Neutral Non-Hydrogenic Spectral Lines,"

J. Chem. Phys. Ref. Data, 5, 209 (1976).

7. N. Konjevic and W. L. Wiese, "Experimental Stark Widths and

Shifts for Isolated Ionic Lines," J. Chem. Phys. Ref.

Data, 5, 259 (1976).

42
Project Title : MEASUREMENT OF F-VALUES IN THE ULTRAVIOLET AND VISIBLE

REGION AND STUDY OF CONTINUOUS EMISSION OF HYDROGEN

NEAR THE BALMER LIMIT

Principal Investigator : Dr. Vladis Vujnovic

Institution : Institute of Physics, University of Zagreb

NBS Monitor : Dr. Wolfgang L. Wiese

NBS Institute or Center and Division : Institute for Basic Standards

Optical Physics Division

Summary Description of Project Goals

The primary aim of the experimental investigation is to provide

data on atomic transition probabilities. As an element of special

interest, phosphorus is introduced into a wall stabilized arc chamber

and the oscillator strengths are determined on a relative scale in the

visible region. The oscillator strengths will be placed on an

absolute scale by using an available absolute value of one of the

lines, which has been determined by another technique (e.g. a lifetime measurement)

The theoretical part of the project is undertaken to shed more

light on the processes responsible for the hydrogen spectrum formation

near the Balmer limit. The experimentally acquired data from the NBS

Plasma Spectroscopy Section are fitted on the basis of a theoretical

analysis

Results and Implications to Date

Measurements were made in a wall stabilized arc. The phosphorus

pentafluoride was introduced into the central portion of the discharge

column, where it mixed with argon introduced through the electrode

ends. For the measurements, four well isolated spectral lines of P I

and four of P II were chosen in the range from 400 to 650 nm. 43
Optical diagnostics and measurements were performed at the axis

of the arc whose diameter was 3 mm. Test measurements showed a linear

increase of the phosphorus spectral line intensities with the length

of the phosphorus-gas layer, and no more than a 5% variation of

intensity during the experimental runs. This observation assures good

mixing of the phosphorus vapour. The optical depth of the spectral

lines was checked. The relative spectral response of the

monochromator was determined by using a tungsten strip lamp and a

carbon arc. The relative spectral response of the monochromator was

determined by using a tungsten strip lamp and a carbon arc. The

oscillator strengths were normalized to the absolutely known

oscillator strength of the spectral line P I 547. 8nm (f=0.038) . The

relative values of the other lines had an error corresponding mainly

to the error of temperature measurements (11500 K+800 K)

;

LINE

PI 507.9 nm 0.0067 + 0.0020

PI 609.7 0.025 0.008

PI 619.9 0.022 0.007

PII 515.2 0.016 0.008

PII 529.6 0.030 0.015

PII 531.6 0.054 0.027

PII 541.0 0.073 0.037

44
During the measurements, corrosion of the gas-filling system was

observed and a decision was made to rebuild the experimental system in

order to prevent any of the corrosive influence and eventual poisonous

effects of the gas used. For this purpose noncorrosive reduction

valves were built in, as well as noncorrosive flow meters and a filter

for HF, which constitutes the greatest impurity in the PF gas. In the

vacuum system, electromagnetic valves were included which render

faulty operation of pumps almost impossible (this applies equally to

the mechanical and the diffusion oil pumps) . The overall system is

remotely controlled from the main control board. In the spring of

1976, the arc instrumentation was refined by a novel high-voltage

ignition of the arc, a remotely controlled high current rectifier, a

0.001 ohm standard resistor, and a digital voltmeter for current

reading to 0.01 A, and a smoothing filter which diminishes the voltage

ripple to less than 1% at 500 V. By operating all components from a

main control panel, and using foolproof sub-systems, a high degree of

reproducibility was obtained and at the same time current adjustments

were facilitated.

Further measurements will be done with this improved version of

the experimental assembly, aimed at the determination of more

oscillator strengths with higher precision and under conditions of

higher safety for the operators. During the construction of the

assembly, a 1-m visible monochromator made by McPherson was obtained

and tested, together with several smaller items, including a deuterium

lamp calibrated at the NBS.

45
Calculation of the Balmer recombination spectrum in the

statistical interpretation was extended to four experimental

situations (ion concentrations of 1.8, 2.9, 5.7 and 9.3 x lCr cm

with the corresponding temperatures of 9900, 10600, 12000 and 13000

K) . By variations of semi-empirical parameters describing the

ionization energy decrease and the quasi-static influence of

electrons, the statistically formed recombination of ionization

energies helped to evaluate the Balmer recombination spectrum which

does not show a sharp limit. In order to match the experimental

situations to the calculated recombination continuum, four other

contributions were added: the H+ continuum, H-* continuum, H

continuum and the line sum (all these contributions according to

evaluations of Roberts and Vbigt from NBS*) . However, the essential

step was in further applications of the dissolution to the line sum.

With no dissolution, any choice of ionization energy decrease produced

a nonobservable increase of the spectrum itensity on the long

wavelength side of the Balmer limit. After comparison of the summed

calculated spectra with the spectra observed at NBS**, agreement was

found for all four experimental situations, using constant semiemipirical parameters, with 5-10% differences in various spectral

regions

.

The project in Zagreb materially assisted the training of five

physics students and the results are incorporated in one diploma (ref

.

1) and one master's thesis (ref. 2) . The determination of Atomic

Transitions Probabilities for phosphorus is important to NBS in

46
continuing work on the critical compilation of atomic reference data

for the NSRDS system. A first critical compilation on phosphorus

several years ago showed large gaps in the data, probably because this

element is chemically rather aggressive and thus difficult to work

with. The resourceful work of the Yugoslavian group will soon provide

accurate data for the neutral phosphorus spectrum, and thus

constitutes a valuable service for atomic reference data.

The high-current hydrogen-arc was developed at NBS several years

ago as a standard of spectral radiance in the ultraviolet. The

emitted continuum radiance must be thoroughly understood in all

wavelength ranges for quantitative applications. Dr. Vujnovic's

theoretical work on this subject appears to be the most promising

solution to provide a reliable quantitative understanding of the

continuous hydrogen spectrum in the principal recombination regions.

References :

* J.R. Roberts and P.A. Voigt, J. Res., NBS, 75A,291 (1971).

** W. L. Wiese, private communication.

List of Publications that Resulted from the Project

1. V. Lokner, "Relative Transition Probabilities and Oscillator

Strengths of PI and PII in the Visi le Region," Diploma Thesis

(in Croatian) , the University of Zagreb (January 1975)

2. V. Ruzdjak, "Hydrogen Spectrum at the Ionization Limit,"

(in Croation) , Master's Science Thesis, the University

of Zagreb (1975)

3. V. Ruzdjak and V. Vujnovic, "Astronomy and Astrophysics,"

(in press, accepted for publication)

47

Project Title ; EIECTRON-ATOM EXCITATION CROSS SECTION MEASUREMENTS

Principal Investigator ; Dr. V. V. Urosevic

Institution ; Institute of Physics, Belgrade University

NBS Monitor ; Dr. G. Dunn

NBS Institute or Center and Division; Joint Institute for Laboratory

Astrophysics

Summary Description of Project Goals

The project is concerned with the absolute cross section

excitation measurement of some hydrocarbons using He excitation cross

section of 4-^-D - 2^-P and 4 ^-S - 2 ^-p transition as the "excitation

standard .

Results and Implications to Date

During 1975 the experimental apparatus for cross section

measurements of excitation of atoms and molecules was transformed into

apparatus for automatic accumulation of experimental data. The

automation of the apparatus has been performed in the first phase as

an experiment for automatic measurements of optical spectra obtained

from the excitation chamber of the apparatus at a defined electron

energy. By changing in succession the electron energy in this

apparatus in the interval 50-500 eV it is possible to measure

simultaneously several excitation cross sections, i.e. for each

spectral line detected, a measured optical spectrum.

The second phase of automization of this apparatus is also being

planned. The purpose of this phase is to measure automatically the

excitation functions of one spectral line for the energy interval of

electrons from 1 - 1000 eV.

49
List of Publications that Resulted from the Project

1. B. Levi, J. Kurepa and B. Panic, "Automatic Measurements of

Optical Spectra of very Small Intensities," XIX Yugoslav

Conference on ETAN, Ohrid, pp 2-5 (June 1975)

.

2. J. M. Kurepa, S. S. Manola and V.V. Urosevic, "The Excitation

Processes of Ammonia Molecules in the Interaction with

Electrons." To be reported on VTth Congress of Mat. Phys.

Astr. of Yugoslavia, Novi Sad (September 1975)

.

50
Project Title : BULK COMPOSITION AND SURFACE PROPERTIES OF GLASS

Principal Investigator : Dr. Velimir Pravdic

Institution : Rudjer Boskovic Institute, Zagreb

NBS Monitor : Dr. Wolfgang Haller

NBS Institute or Center and Division : Institute for Materials Research

Inorganic Materials Division

Summary Description of Project Goals

The objectives of this project have been to study the surfaces of

glasses of veil defined bulk composition and to find correlations

be-btfsen selected surface parameters and the bulk chemical composition.

In spite of extensive research into the structure, chemical

composition, and properties of glasses, a clear understanding on how

the bulk composition and the chemical and physical treatments

influence surface properties is still largely missing. A fuller

understanding of the correlations between bulk and surface properties

could be of considerable technological importance wherever glass is

being used.

The properties of glass surfaces studied include adsorption

phenomena and charge density and distribution, as measured by

electrokinetic techniques of streaming potential and surface

conductivity, by ESR hyperfine splitting, and by heats of immersion

and continuous flow microcalorimetry.

Results and Implications to Date

The samples of glass, in powder or capillary forms, were supplied

by the NBS Inorganic Glass Section. They were well characterized with

respect to their chemical composition, concentration of minor

51
constituents (impurities) , and structural elements (pore size and

volume, domain development) . The surface parameters were determined

in the Laboratory of Electrochemistry and Surface Phenomena, of the

Rudjer Boskovic Institute, using the techniques and the expertise

developed in this group.

Glasses so far studied have been, partly, commercially available

samples such as crystalline quartz, fused silica, doped silica, Vycor,

Pyrex (7740) , as veil as a selection of controlled pore glases

produced in the NBS Laboratories

.

It has been shown that electrokinetic measurements do not reveal

large differences between pure and doped silica and quartz. Alumina

impurities tend to decrease the negative potentials in quartz, but do

not influence the properties of fused silica. Application of surface

charge formation criteria based on the model of the diffuse double

layer indicate that the mechanism of pH dependent adsorption of

potential determining ions is dominant for quartz and silica. The

incidence of surface boronol gorups in glasses with an appreciable

amount of B-O., (as in Vycor and Pyrex) results in a behavior

characteristic for a constant surface charge model. Effective charge

desitities, based on observations on both these models, should not

TO 9 exceeed 10 unit charges per cm . Indeed, these observations were

borne out by experiments involving both measurements of electrokinetic

straming current and of ESR hyperfine splitting for -^Ag adsorbed

from aqueous solutions. Characteristic values found were 3 x 10 and

12 2

7 x 10 unit charges per cm , respectively.

52
Heats-of-immersion microcalometry with a series of dipolar

liquids using controlled pore glasses revealed that the contribution

of polar forces to total interfacial energy was increasing from 35%

for a mean pore size of 225 nm, to 38% for 55 nm, and to 45% for 15

nm, the smallest pore size material studied. The integral heats of

immersion into water were measured and found in the range of 0.30 +

0.03 J/m for all the 4 types of controlled pore glasses studied,

identifying these as exhibiting moderately high energy surfaces.

Flow microcalorimetric studies were used to investigate the

energies of adsorption of a homologous series of lower normal

aliphatic alcohols from hexane solutions. It was found that the

integral molar heats of adsorption are almost constant in the series

from methanol to n-pentanol, and amounts to 15.4 + 0.5 kJ/mol. It was

also found that the surface area occupied per alcohol molecule is 0.17

2

+ 0.01 nm .

Surface conductivity studies for fused silica and pyrex surfaces

in methanol and acetronitrile indicated a twofold mechanism: one

operative at lower temperatures (below 10° C) characterized with low

energies of activation, and another at higher temperatures with high

energies of activation. Surface conductivities at silica surfaces

were one order of magnitude lower than those observed at pyrex

surfaces

Continuation of the present research work is directed primarily to

further investigation of adsorption properties at the glass/ solution

interface. Modified surfaces with inorganic and organic ligands will

53
be studied, using as adsorbates polyelectrolytes , organic dyes,

polypeptides, and, possibly, some well characterized biological

substances. This research is aimed at understanding the behavior of

glass in the presence of biologicals, in terms of adsorption

energetics and interfacial electrification, and to see to what degree

the surface ligands screen the influence exerted by bulk properties of

glass. Results of this research could provide useful data for the

application of glass as containers in the biological and chemical

container industry.

A further area of application is the use of quartz, silica and

some aluminosilicate glasses as models in studies of adsorption and

immobilization of organic substances in marine sediments, a

contribution towards problems of environmental effects and pollution

control.

List of Publications Which Resulted from the Project

1. J. Jednacak, M. Hudomalj, V. Pravdic and W. Haller, Electrokinetics of Glass Surfaces. I. Charge Densities at the Solid/Gas

and the Solid/Liquid Interfaces of Porous Glasses," Croat.

Chem. Acta 44, 149 (1972)

.

2. J. Jednacak and V. Pravdic, "Electrokinetics of Glass Surfaces,"

Proc. 3rd. Yugoslav Congress for Pure and Applied Chemistry,

Ljubljana, June 1972.

3. J. Jednacak, V. Pravdic and W. Haller, "The Electrokinetic

Potential of Glasses in Aqueous Electrolyte Solutions,"

J. Colloid Interface Sc. 49, 16 (1974) .

'

4. V. Mikac-Dadic, J. Jednacak-Biscan and V. Pravdic, "Surface

Conductivity at the Glass/Liquid Interface," Meeting of the

Chemical Society of Croatia, Zagreb, February 1975.

5. V. Mikac-Dadic, J. Jednacak-Biscan, V. Pravdic and W. Haller,

"Mechanism of Electric Conductance of a Glass Surface in Contact

with a Liquid Phase," 4th Yugoslav Symposium on Electrochemistry,

Dubrovnik, June 1975.

54
J. Jednacak-Biscan, V. Mikac-Dadic, V. Pravdic and W. HaHer,

"Surface Conductivity of Glass at the Solid/Liquid Interface"

52nd Symposium on Colloid and Surface Science, Knoxville,

Term., June 1978.

J. Jednacak-Biscan, V. Mikac-Dadic, V. Pravdic and W. Haller,

"Surface Conductivity of Glass at the Solid/Liquid Interface,"

(submitted to J. of Colloid and Interface Science)

55

Project Title ; THEORETICAL INVESTIGATIONS ON PHYSICAL SURFACES

Principal Investigator ; Prof. M. Sunjic

Institution ; Rudjer Boskovic Institute, Zagreb

NBS Monitor ; Dr. J. W. Gadzuk

NBS Institute or Center and Division ; Institute for Basic Standards

Optical Physics Division

Summary Description of Project Goals

A theoretical investigation of crystal surfaces by means of

spectroscopic methods will be carried out. Applying the many-body

theory, the x-ray photoemission and photoabsorption phenomena will be

analyzed. Special attention will be paid to the determination of

electron attenuation lengths in x-ray absorption and Auger processes,

the excitation of both volume and surface plasmons in x-ray

photoemission, and inelastic processes in field-electron and -ion

emission.

This work represents a continuation of a scientific collaboration

between Dr. J. W. Gadzuk (NBS) and Dr. M. Sunjic which started two

years ago.

Results and Implications to Date

The major problem we have been considering over the past year

pertains to the many-body modifications to the photoelectron lineshape

of core state electrons of atoms in solids and on surfaces. Amongst

the important processes, we include electron-hole pair shakeup,

plasmon satellites, phonon broadening, and Auger decay

broadening. We have chosen to formulate our problems in a space-time

(rather than momentum energy) picture. The added clarity (at the

57
expense of some mathematical rigor) has made our work considerably

more accessible and thus useful to non-many-body theorists.

Specifically, we have continued our studies into time dependent

relaxation effects which were first published in our Physical Review

paper.* As a result, we have been invited to give back to back

lectures at such meetings as the "International Photoemission

Sympsium" which was held in Ndordwijk, Netherlands in September 1976.

Vfe held special tutorial sessions on many-body effects in surface

spectroscopies at a July 1976 Gordon Conference on Electron

Spectroscopy. We have broken new ground in the area of coupled phonon

excitation hole decay processes in x-ray photoemissions** and will

continue work in this area until a satisfactory resolution of some

apparent paradoxes in existing theories is obtained. Our plans are to

spend time together in September 1977 for our, at least yearly,

coordination and writing.

List of Publications and Lectures that Resulted from the Project

1. J.W. Gadzuk, "Time Scales and Plasmon Satellites in XPS" and

M. Sunjic, "Scattering Effects in Photoemission from Localized

Levals in Solids" in "Proc. of an International Symposium on

Photoemission," European Space Agency Spec. Pub. 118 (Dec. 1976).

2. J. W. Gadzuk and M. Sunjic, Special tutorial lectures at a

July 1976 Gordon Conference on Electron Spectroscopy (1976 )„

* J. W. Gadzuk and M. Sunjic, Phys. Rev. B12, 524 (1975). ** M. Sunjic and A. Lucas, Chem. Phys. Letters 42, 462 (1976),

58
Project Title : SYNTHESES AND PROPERTIES OF FLUORIDE COMPLEXES

Principal Investigator : Professor Dr. Joze Slivnik

Institution : Jozef Stefan Institute , Ljubljana

NBS Monitor : Dr. T. D. Coyle

NBS Institute or Center and Division: Institute for Materials Research

Inorganic Materials Division

Summary Description of Project Goals

This work deals with investigations of reactions of transition

element fluorides with anhydrous hydrazine, the synthesis and

isolation of hydrazinium fluorometalates containing first row

transition elements, the preparation and characterization of xenon

(II) and xenon (VI) fluorometalates of the first row transition series

for the following purposes:

1. to develop new or improved methods of chemical synthesis

for inorganic fluorine containing compounds

2. to advance the techniques of sample purification

3. to determine accurately the chemical and physical

properties of isolated compounds where data will

contribute to the understanding of such compounds

Results and Implications to Date

This is a third year report (the final report) and contains new

results on the following topics:

1. Investigations of reactions of transition element fluorides

with anhydrous hydrazine.

2. Syntheses of hydrazinium f luorometalates of the first

transition series.

3. Synthesis and property studies of compounds formed between

xenon difluoride and fluorides of elements of the first

transition series.

59
In the course of the present work four MF -N H systems have been

investigated, with M being nickel, chromium or iron. The following

metal fluoride-hydrazine addition compounds have been isolated,

described and characterized: Ni fls£> H^)2 . g

F

2

, CrF3 -31^ H4, 2CrF2'- 31^ H4,

and FeF

?

„*2ISLH . In addition some other compounds (e.g. Ni (N-H.)., (H~

0) 2

F

2

, (N^) Ni(N2E^)

2 (0H)

5

, (N^ ) 3 Cr2

F

4 (0H) 5

- nl^O) were found as

products of partial hydrolysis in these systems. Preliminary

experiments were carried out with iron (III) fluoride and hydrazine,

and it was found that a reduction to iron (II) took place.

The details of the preparative procedures are given in the

publications listed, as are the chemical analyses of the isolated

compounds. Some compounds were characterized also by thermal

analysis, i.r. spectroscopy and magnetic measurements.

Hydrazinium fluorometalates , with the metal being nickel, cobalt,

or copper, were isolated and characterized. In order to synthesize

hydrazinium fluorocobaltate and fluoronickelate first the reaction

between a water solution of hydrazinium (1+) fluoride and cobalt (2+)

hydroxide or nickel (2+) hydroxide or nickel (2+) hydroxide

respectively was tried. In the case of cobalt, (N 2^)2 CbOF2«H2P was

obtained while in the case of nickel, NiF2* 2^^* 2H2O was formed.

Anhydrous compounds were obtained by dehydration in vacuum. N2H5O0F3

was synthesized by dissolving cobalt (II) fluoride in the melt of

hydrazinium (1+) fluoride. In an analogous way 3NiF2

- 2^1^ was

synthesized, while the analogous cobalt compound was obtained by

thermal decomposition of hydrazinium (1+) trifluorocobaltate (II)

.

60
Hydrazinium (1+) fluorocuprate was isolated by the reaction between

hydrofluoric acid and copper hydrazidocarbonate hydrate. All isolated

compounds were characterized by chemical analysis, x-ray powder

diffraction patterns, i.r. spectroscopy, magnetic measurements and

thermal analyses.

It was found that hydrazinium fluorometalates are very

interesting starting materials for the reactions with xenon

difluoride, or xenon hexafluoride, because the corresponding fluorides

are formed during this reaction. Fluorides thus obtained are very

reactive and combine to form complex compounds. For example, in the

case of the reaction between iron (III) fluoride and xenon hexafluoride

the starting materials were recovered unchanged while in the case of

the reaction between N2H5FeF5 and xenon hexafluoride the complex

compound XeFg-FeF, was formed. It was also found that during the

reactions between hydrazinium fluorometalates (manganese and chromium)

and xenon difluoride, the corresponding ammonium fluorometalates are

formed (NH,MnFr and NH^CrF^) instead of xenon fluorometalates (XeF2 •

MnF and XeF -2CrF ) which are obtained during the reactions between

corresponding fluorides and xenon difluoride.

In the case of the reactions between hydrazinium fluorometalates

and xenon hexafluorides the same complex compounds are formed as with

corresponding fluorides if the reaction takes place. The following

xenon (VI) fluorometalates were isolated during this study:

4XeF r .TiF„, XeF *TiE\, XeF . 2TiF . 4XeF .MnF , 2XeF -MnF , XeF -MnF , 6 4' 6 4' 6 4 6 4 6 4 6 4

XeF •2MnF., XeF * CoF . and XeF -FeF . 6 4' 6 3 6 3

61
This project, in addition to generating data and information on

the chemistry of fluorine compounds, has also resulted in the

development of methods for preparation, purification and characterization of fluorine compounds.

List of Publications that Resulted from the Project

1. P. Glavic, A. Bole and J. Slivnik, "Manganese (II) Fluoride - Hydrazine Complexes," J. Inorg. Nucl. Chem. , 35, 3979 (1973).

2. P. Glavic, A. Bole and J. Slivnik, "Reactions of Zirconium,

Hafnium and Cerium Tetrafluoride with Hydrazine," J. Inorg.

Nucl. Chem., 37, 1316 (1975).

3. P. Glavic, J. Slivnik and A. Bole, "Cadmium (II) Fluoride - Hydrazine Complexes," J. Inorg. Nucl. Chem., 37, 345 (1975).

4. P. Glavic, J. Slivnik and A. Bole, "Reaction of Nickel (II)

Fluoride with Hydrazine," J. Fluorine Chm. , (in press)

.

5. J. Slivnik and A. Rahten, "Die Synthese und einige

Eigenschaften von Hydrazinium(l+) Tetrafluoromanganat (II)

und Hydrazinium(2+) Pentafluoroferrat (III) . Vestn. Slov. Kern. Drastva (Bull. Slov. Chem. Soc), 22 36 (1975).

6. J. Slivnik and A. Rahten, "Die Verbindungen von Elementen

der ersten Ubergangsreihe mit Hydrazin und Fluor; Verbindungen

von Kobalt un Nickel," Vestn. Slov. Kern. Drustva (Bull. Slov.

Chem. Soc), (submitted for publication June 1976) .

7. B. Zemva and J. Slivnik, "On the Xenon - Fluorine Reactions,"

J. Inorg. Nucl. Chem. Supplement 173 (1976)

.

8. B. Zemva, J. Slivnik and M. Bohinc, "On the Syntheses of Xenon

Fluorotitanates (IV) , " J. Inorg. Nucl. Chem., 38, 73 (1976).

9. M. Bohinc, J. Grannec, J. Slivnik and B. Zemva, "On the

Syntheses of Xenon Fluoromanganates (IV) , " J. Inorg. Nucl.

Chem., 38, 75 (1976).

10. J. Slivnik, B. Zemva, M. Bohinc, D. Hanzel, J. Grannec,

P. Hagenmuller, J. Inorg. Nucl.Chem., 38, 997 (1976);

"On the Syntheses and Some Properties of Xenon (VI)

Fluoroferrate(III) and Fluorocobaltate(III)

.
Project Title : A MODULAR COMPUTER SYSTEM FOR REAL-^TIME DATA REDUCTION

AND CONTROL IN BIOMEDICAL EXPERIMENTS

Principal Investigator: Professor Zvonimir Damjanovic

Institution : Multidisciplinary Centre of Belgrade University

NBS Monitor : Mr. T. N. Pyke, Jr.

NBS Institute or Center and Division: Institute for Computer Sciences

and Technology, Computer Systems

Engineering Division

Summary Description of Project Goals

The main purpose of the project is to improve interaction between

the experimenter and the computer in biomedical or other laboratory

experiments. The basic assumption is that this goal can be achieved

by designing a modular structure, either in the hardware, the software

or combined hardware-software sense, that will give the experimenter

flexible command over the experimental apparatus without the need for

him to become familiar with the detailed operation of the supporting

computer. The investigations were carried out in four basic

directions

a. Theoretical research in the area of formal languages

with the purpose of providing a sound critical basis

for the evaluation of alternatives in eventual future

development of suitable problem-oriented languages.

b. Research in hardware implementation of high-level

programing languages with the purpose of providing

enough elements for eventual future synthesis of

computing structures.

c. Examination of representative biomedical processes

and development of suitable mathematical models with

the purpose of providing enouch material for the

development of some basic modular programs applicable

to several biomedical experiments.

63
d. Practical computer applications in processing signals

from biomedical experiments with the basic purpose of

studying input-output devices necessary for the

realisation of mutual communication in the system

composed of man, computer and the biological object.

Results and Implications to Date

Several major steps have been completed in the development of a

modular computer system for real time data reduction and control in

biomedical experiments. This modular system requires that the

interfaces between the human scientist or laboratory technician and

the computer system be well tailored to human use and to each specific

application. Special attention must be given in this man-computer

relationship to the triad involving the human user, the control

computer, and the experimental apparatus.

Three specific accomplishments have laid the basis for the

flexible development of experiment control languages that are

individually tailored to specific experimental applications. Specific

results in formal language theory and in hardware/ software

implementation schemes for high level programming languages have been

combined with a unique approach to generating an application-specific

compiler for the laboratory data acquisition and control environment.

These first steps have been combined with the in-house testing of a

minicomputer-based data acquisition and control sytem with which these

techniques will be used to develop and demonstrate the project's

ultimate goal—that of significantly improved control and flexibility

in an experimenter's work with a laboratory control computer and with

the associated experimental apparatus.

64
List of Publications that Resulted from the Project

1. J. Polajnar, M.A. Thesis on results in formal language theory.

2. B. Jankovic, M.A. Thesis on high level programming language

structures.

3. D. Braticevic, M.A. Thesis on compiler generation.

65

Project Title : RADIATION DOSIMETRY AND RADIATION CHEMISTRY

Principal Investigator ; Dr. I. Draganic

Institution : Boris Kidric Institute of Nuclear Sciences, Vinca

NBS Monitor : William L. McLaughlin

NBS Institute or Center and Division : Institute for Basic Standards

Center for Radiation Research

Applied Radiation Division

Summary Description of Project Goals

The project concerns work on chemical dosimetry and radiation

chemistry in high-intensity radiation fields. The studies are focused

on the most promising measurement systems, whose practical ranges of

reliable application are to be determined. This mainly comprises

ranges of absorbed dose, dose rate, and also some practical

conditions, e.g. in-situ and/or bulk measurements in industrial

radiation processing. During the first year, suitable methods for

absolute calibration were established and have subsequently been used

for testing chosen chemical dosimetry systems. The later stages have

been devoted to the radiation-chemical studies of processes and

mechanisms of the overall "dosimetric" reaction, in order to achieve

improved measurement capability and metrology standards for industrial

applications.

Results and Implications to Date

The results of this collaborative program have proven to be

highly successful in attaining the initial goals of the project. In

fact, the mutual benefit of achieving new, practical methods of

accurate measurement for radiation processing industries goes far

beyond the original scope of the program. Some of the methods

67
developed here, using solid and liquid forms of dye derivatives, will

provide NBS with improved meassurement capability for intense

radiation fields. They will also be used routinely in a new Yugoslav

program supported in part by the United Nations Development Program

for improving industrial and medical materials by means of radiation

treatment. Beyond that, the methods are expected to play an important

role on an international scale and contribute to applied radiation

metrology and quality control.

A breakthrough was achieved in the final stages of the work, in

that the kinetics of radiolytic dye formation in leuco forms of

triphenylmethane dye systems were explained for the first time, thus

giving credence to the observation of the absence of rate dependence

of the response of these systems in high flux density radiation

fields.

The collaboration is expected to continue on a basis of mutual

scientific interest.

List of Publications Which Resulted from the Project

1. B. Radak, P.E. Hjortenberg and N.W. Holm, "A Calorimeter for

Absolute Calibration of Thin Film Dosimeters in Electron

Beams," Proceedings of the IAEA Symposium on Dosimetry in

Agriculture, Industry, Biology and Medicine, pp. 311-318,

IAEA, Vienna (1973).

2. I. Draganic and B.L. Gupta, "Some Current Tendencies in

Chemical Dosimetry," Ibid., pp. 351-361.

3. W.L. McLaughlin, P.E. Hjortenberg and B.B. Radak, "Problems

in Absorbed Dose Measurements by Thin Films," Ibid., 557.

4. W.L. McLaughlin, M. KDsanic and I. Draganic, "Extending

the Linear Gamma-Ray Response of Pararosaniline Cyanide

Solutions from 0.1 to 1 Megarad," Ibid., pp. 362-366.

68
5. P.E. Hjortenberg and W.L. McLaughlin, "Use of Radiochromic

Dye Systems for Dosimetry/1 Proceedings of Regional

Conference of Radiation Protection, Jerusalem, Israel,

Marcn (1973)

6. W. L. McLaughlin and M.M. Kosanic, "The Gamma-Ray Response of

Pararosaniline Cyanide Dosimeter Solutions," Int. J. Appl.

Radiat. Isotopes, 25, pp 249-62 (1974).

7. B. Radak, M.M. Kosanic, M.B. Sesic and W.L. McLaughlin,

"A Calorimetric Approach to the Calibration of Liquid

Dosimeters in High-Intensity Electron Beams," Advances in

Bio-Medical Dosimetry (IAEA Symposium) , paper IAEA-SM-193/70,

IAEA, Vienna, pp. 633-641 (1975)

8. M.M. Kosanic, M.T. Nenadovic, B.B. Radak, V.M. Markovic

and W.L. McLaughlin, "Liquid Radiochromic Dye Dosimetry for

Continuous and Pulsed Radiation Fields Over a Wide Range

of Energy Flux Densities," Int. J. Appl. Radiat. Isotopes,

28, pp 313-21 (1977)

9. W.L. McLaughlin, K. Schested, V.M. Markovic, M.M. Kosanic

and M.T. Nenadovic, "The Kinetics of Dye Formation by

Pulse Radiolysis of Leuco Cyanides of Triarylmethane Dyes

in Aqueous or Organic Solution" Rad. Phys. Chem., in press

(1978)

10. W. L. McLaughlin, A. Miller, M.M. Kosanic, M.M. Markovic and

B.B. Radak, "Kinetics of Dye Formation by Pulse Radiolysis of

Leucocyanides of Triarylmethane Dyes in Polymeric Solution"

(to be published in Rad. Phys. Chem., 1978)

11. W. L. McLaughlin, "Solid-Phase Chemical Dosimeters,"

Sterilization bv Ionizing Radiation (eds. E.R.L. Faughran and

A.J. Goudie, Multiscience Publishers Ltd., Montreal, pp. 219-252

(1974)

12. I. Draganic, "Liquid Chemical Dosimeters," Ibid, pp. 253-269.

13. W. L. McLaughlin, "Radiation Measurements and Quality Control,"

Proceedinqs of International Meeting on Radiation Processing

(eds. J. Silverman ana A. van Dyken) , Pergamon Press, Oxford

(1976). (Rad. Phys. Chem. 9, pp 147-181, 1977).

14. J. C. Humphreys, W. L. McLaughlin, B. B. Radak, A. Miller

and T. A. Olejnik, "The Response of Plastic Dosimeters to

Gamma Rays and Electrons at High Absorbed Dose Rates," (to

be published in Rad. Phys. Chem, 1979)

69
15. B. B. Radak, W. M. Markovic and W. L. Mclaughlin, "Commissioning

Dosimetry of a Versatile Irradiation Plant at the Boris Kidric

Institute of Nuclear Sciences - Vinca, Yugoslavia" (to be

published in Rad. Phys. Chem, 1979)

.

16. V. M. Markovic, R. Eymery and H. C. Yuan, "A New Approach to

Go-60 Plant Design for Introduction of Radiation Sterilization

in Developing Countries," Rad. Phys. Chem. 9, pp 625-631, 1977.

70
APPENDIX I

SFCP (PL-480) BACKGROUND HISTORY

Since Fiscal Year (FY) 1961 the National Bureau of Standards has

had an active Special Foreign Currency Program (SFCP) in India,

Israel, and Pakistan. During 1970, Yugoslavia was added to the list

of countries. Projects in Poland and the Arab Republic of Egypt

became active after 1972.

The relevant US laws, such as PL-480 of the 83rd Congress

pertaining to the use of SFCP funds, challenge imaginative

implementation at the same time as they offer the opportunity for

international collaboration of universal benefit. In the mission area

of NBS and in joint research with the available countries, successive

directors of NBS have called for an effective program. To this end,

Mr. H. Steffen Peiser, as designated program manager, under the

supervision of Dr. E. L. Brady, Associate Director for International

Affairs, has received wide-ranging support, which is hereby gratefully

acknowledged

Stated Policy for NBS/SFCP Grants

NBS/SFCP grants provide supplementary resources that provide an

appropriate means for accomplishing NBS objectives, consistent with

U.S. foreign policy objectives. NBS criteria for this purpose are:

"1. All projects must be of scientific or technological

excellence

2. All projects must be within the mainstream of NBS interests

or contribute directly to NBS effectiveness.

71
3. All projects must benefit both the U.S. and the participating countries:

(a) NBS/SFCP funds must not merely replace otherwise

available country funds; and

(b) Individuals or institutions abroad must not become

primarily dependent upon NBS for long term support.

4. All projects must be followed closely by NBS staff members

working in related areas. Thus, one or more NBS staff

members should maintain a continuing direct relationship

with the foreign person or group. This relationship should

be strengthened by visits in either or both countries.

5. NBS involvement with a technical institution of another

nation should be consistent with U.S. foreign policy.

For example, relationships with sister institutions,

staff exchanges, and visits should be carried on in the

context of overall U.S. objectives in its relationships

with the other country.

6. NBS staff travel to participating foreign countries should

be exploited, when practical, by suitable additional

visits to identify additional targets for bilateral

benefit or to provide additional strength to existing

relationships. Such travel should be coordinated with

the NBS/SFCP Manager."

72
APPENDIX II

INDEX OF INSTITUTES

Institute Page (s)

BELGRADE

LJUBLJANA

VINCA

ZAGREB

University of Belgrade

Institute of Physics

Multidisciplinary Center

Jozef Stefan Institute

Boris Kidric Institute

Rudjer Boskovic Institute

University of Zagreb

37,49

63

7,15,59

25,67

11,51,57

21,31,43

73
APPENDIX III

ALPHABETIC LIST OF PRINCIPAL INVESTIGATORS

Principal Investigator

University, Institute

or Laboratory Page (s)

Blinc, R.

Bonefacic, A.

Branica, M.

Damjanovic, Z.

Draganic, I.

Konjevic, N.

Kdsta, L.

Piljac, I.

Pravdic, V.

Slivnik, J.

Sunjic, M.

Urosevic, V.

Vujnovic, V.

Ziribov, K. F.

Jozef Stefan 15

University of Zagreb 31

Rudjer Boskovic Institute 11

University of Belgrade 63

(Multidisciplinary Center)

Boris Kidric 67

University of Belgrade 37

(Institute of Physics)

Jozef Stefan 7

University of Zagreb 21

Rudjer Boskovic Institute 51

Jozef Stefan 59

Rudjer Boskovic Institute 57

University of Belgrade 4 9

(Institute of Physics)

University of Zagreb 43

(Institute of Physics)

Boris Kidric 2 5

74
APPENDIX IV

ALPHABETIC LIST OF NBS MONITORS

NBS Monitor Division Page(s)

Coyle, T. D.

Dunn, G. H.

Gadzuk, J. W.

Haller, W.

Hastie, J. W.

LaFleur, P. D.

McLaughlin, W. M.

Pyke, T. N.

Reed, R. P.

Reneker, D. H.

Taylor, J. K.

Wiese, W. L.

313.01 15

274.00 (Boulder) 49

232.00 57

313.02 51

313.01 25

310.00 7

243.02 67

650.02 63

275.03 (Boulder) 31

311.03 15

310.00 11,21

232.07 37,43

75
NBS-114A (REV. 7-73)

U.S. DEPT. OF COMM. BIBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OR REPORT NO. NBS TN 986

2. Gov't Accession

No.

4.

V TITLE AND SUBTITLE

NBS SPECIAL FOREIGN CURRENCY PROGRAM IN YUGOSLAVIA

1973-1978

3. Recipient's Accession No.

5. Publication Date September 1978

6. Performing Organization Code

7. AUTHOR(S) Doris M. Bluebond, Robert S. Marvin, and

H. Steffen Peiser

8. Performing Organ. Report No.

9. PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

10. Project/Task/Work Unit No.

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12. Sponsoring Organization Name and Complete Address (Street, City, State, ZIP)

Same as No. 9

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Library of congress Catalog Card Number 78-600093

16. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bibliography or literature survey, mention it here.) An overview is given of grants awarded by the National Bureau of Standards

under the Special Foreign Currency Program (SFCP) or by the U.S. -Yugoslav Joint

Board. Each grant is identified by title, principal investigator, institution in

Yugoslavia, NBS monitor, and the Monitor's organizational unit within NBS. The

work is then described briefly under the three headings "Summary Description of

Project Goals," "Results and Implications to Date," and "List of Publications that

Resulted from the Project." To demonstrate the relevance of such grants to the

programs of NBS, the grant descriptions are ordered by NBS institutes and divisions.

The significance and purpose of the NBS/SFCP grant programs are discussed in the

Foreword and the Introduction. The NBS monitors and the program manager judge

this grant program to have had a high benefit to cost ratio from the viewpoint of

NBS.

17. KEY WORDS (six to twelve entries; alphabetical order; capitalize only the first'letter of the first key word unless a proper name; separated by semicolons) Din-.4-l~r.-l v»^^«^„«u ____„ j. • • x. j. • n • j_ • c- • Binational research cooperation; international scientific

cooperation; physical science research administration; research planning; scientific

research abstracts; Special Foreign Currency Program; Yugoslavia science and technology.

18. AVAILABILITY fy! Unlimited

~2. For Official Distribution. Do Not Release to NTIS E Order From Sup. of Doc, U.S. Government Printing Office Washington, D.C. 20402, SD Stock No. SN003-003

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