bluuebunny/crossref_metadata_2025 huggingface dataset:
Strukturveränderungen von Tonmineralien unter verschiedenen thermodynamischen Bedingungen (III). Transformative Umwandlungen von Mineralen der Kaolinit‐Gruppe unter erhöhtem Druck bei Anwesenheit von mineralisierenden Lösungen
Authors: Frank‐Kamenetzkij V. A. , Kotov N. V. , Goilo E. A. , Schitov V. A.
Published: July 2007

In the earlier papers (I and II, Frank‐Kamenetzkij et al., 1966, 1968) data regarding the structural and facial changes in kaolin group minerals under conditions of interaction with hydrothermal chloride solutions of K, Na, Ca, Mg at P = 900 kg cm−2. T = 200–500°C were dis‐ cussed. In the present paper the results of these investigations are summed up.

The diffractometrical, electronographic and electron microscopic investigations of initial, intermedial and final phasis mainly of layered silicate and aluminous silicates show a cristallographic inheritance of structures during the transformation of kaolinite into montmorillonite, micas and mixed layered facies (rectorit, tosudit etc.) This is seen in the retention of the main features in the basal plane, in the character of population of the octahedral positions, in the tendency to retain the sequence of alternation and imposition of layers (polytype), and in the processes of deformation that the structures of the initial minerals undergo during such changes. The wide participation of ordered and disordered mixed‐layered structures in these reactions is the result of structural changes by transformatical means. At the same time, the chemical nature of the medium exerts considerable influence on the course and nature of the resulting structures. Thus, the mechanism of transformational thermal changes of aluminium silicates, which is already known for “dry‐systems”, is observed to a great extent in the case of complex polycomponental systems under H2O pressure and is characterised by the specific individual features discussed in this paper.
Ermittlung molekularkinetischer Daten aus Keimbildungsuntersuchungen. Keimbildung von PbS auf NaCl und NaF im UHV
Authors: Schoenborn W.
Published: July 2007

Es wird untersucht, inwieweit Vorstellungen über das Kondensationsverhalten von Atomen auf das Kondensationsverhalten von Molekülen übertragbar sind. Dazu wird das System PbS/NaCl und PbS/NaF mit dem System Edelmetalle/NaCl verglichen. Als charakteristische Größe wird die Grenzkeimdichte N8 herangezogen, die gemäß Modellvorstellungen eine Funktion der molekularkinetischen Größen Adsorptionsenergie Qad, Diffusionsenergie Qd, Schwingungsfrequenz v0 und der Kondensationsparameter Substrattemperatur T und Bedampfungsrate N↓ ist.

Im Bereich von 100 bis 315°C und bei einer Bedampfungsrate von 2,7 × 1013 cm−2 × s−1 zeigt die Grenzkeimdichte etwa die nach dem Modell zu erwartende Temperaturbhängigkeit. Zwischen den Systemen PbS/NaCl und PbS/NaF konnten keine Unterschiede in der Grenzkeimdichte festgestellt werden. Folgende Werte wurden ermittelt: Qad ≈ 0,54 eV; Qd ≈ 0,22 eV; v0 ≈ 108 s−1. Qad und Qd unterscheiden sich nur wenig von den Werten für Au und Ag auf NaCl. Jedoch ist v0 um 4 Größenordnungen kleiner als der für das System Edelmetalle/Alkalihalogenide als gültig angenommene Wert von ≈ 1012 s−1.
Untersuchungen zur Schichtbildung von Gold auf Natriumchlorid‐Spaltflächen
Authors: Hayek K. , Schwabe U.
Published: July 2007

Keimbildung und Epitaxie von Goldaufdampfschichten auf im Vakuum hergestellten NaCl‐Spaltflächen wurden als Funktion der Substrattemperatur und des Wasserdampfdruckes untersucht. Um zu entscheiden, ob das elektronenmikroskopische Bild die Struktur sehr dünner Schichten richtig wiedergibt oder ob beim Kohleabdruck Artefakte entstehen, wurde ein Teil der Schichten mit einer Tantal‐Wolfram‐Legierung fixiert. Ein Vergleich fixierter und unfixierter Schichten ergab Unterschiede nur von Raumtemperatur abwärts, hervorgerufen durch den Wassergehalt der Kohle. Messungen der Kristallitzahl an sehr dünnen Schichten, die bei −140°C aufgedampft und mit Ta‐W fixiert worden waren, zeigten nur geringfügige Abhängigkeit von der Schichtdicke.

Weiter wurde der Einfluß aufgedampfter Kohlezwischenschichten auf Orienterung, Dekoration und Keimzahl von Gold‐ und Silberaufdampfschichten auf (100) NaCl untersucht. Es wurde eine geringere Fernwirkung der Orientierung gefunden als bisher beschrieben. Die maximale Dicke der Kohleschicht, durch die hindurch noch Orientierung beobachtet wurde, war für Gold bei 250°C 9–12 Å, für Silber bei 150°C 7–9 Å.
A crystallizer for the investigation of conditions of growth of single crystals from solutions
Authors: Novotný J.
Published: July 2007

The crystallizer of the Walker‐Kohman type for isotherm growing of single crystals from solutions is described which has been designed to provide the maintenance of constant conditions of crystallization chosen in advance and the investigation of the influence of these conditions on the resulting structural regularity of the crystals as grown. The temperature of the solution can be kept inside the interval from 30 to 60°C, with an accuracy ±0.002°C. The equipment allows the setting and keeping the requested value of supersaturation, hydrodynamic conditions, thermal stabilization of the crystallization solution and enables the optic and gravimetric observing of the single crystal during its growth. The total function of the described equipment was tested by growing single crystals of triglycine sulphate at 52°C.
Setting of Crystals on the Precession Camera
Authors: Jost K. H.
Published: July 2007

The general case of the setting of crystals on the procession camera is dealt with.

Es wird der allgemeine Fall der Justierung von Kristallen auf der Precession‐Kamera behandelt.
Über die Morphologie des Diamanten
Authors: Petrov V. S.
Published: July 2007

Es wird eine kurze Übersicht über die bisherige Diskussion zur Morphologie des natürlichen Diamanten gegeben und ein neuer Standpunkt über den Mechanismus der Entstehung der morphologischen Besonderheiten des Diamanten zur Diskussion gestellt.
Computergesteuertes Zeichnen stereographischer Projektionen von Kossel‐Linien und ihre Anwendungen zum Studium tetragonaler Verzerrungen
Authors: Ullrich H.‐J. , Thiele K. , Däbritz S. , Schreiber H. , Götze K. , Feldhofer F.
Published: July 2007

Zur Ermittelung der Gitterkonstanten und der Symmetrieelemente sowie zur Orientierungsbestimmung von mikroskopisch kleinen Bereichen kompakter Proben wird die Kossel‐Technik eingesetzt, wobei stereographische Projektionen von Kossel‐Linien als Auswerte‐Hilfsmittel herangezogen werden. Es werden Varianten eines Computerprogramms beschrieben, mit dem sich stereographische Projektionen von Kossel‐Linien bzw. Ausschnittsstereogramme bei einem Minimum von Eingabewerten zeichnen lassen. Die Nützlichkeit der Stereogramme wird an Hand von Beispielen belegt, wobei besonders auf das Studium tetragonaler Verzerrungen in kubischen Substanzen eingegangen wird.

Stereographic projection of Kossel‐lines are often used to interprete Kosselpatterns for determination of lattice constants and orientation relations. This paper describes computer programs for plotting stereographic projections with a minimum of input data. The usefullness of such projections are shown on examples of tetragonal stressed FeAl‐lattice ond α–β‐transformation of Co.
Die Untersuchung der Wachstumsstruktur von Quarzkristallen durch Ätzen
Authors: Christoph A.
Published: July 2007

Die Versuchsbedingungen, die durch Ätzen von Quarzproben außer den Durchstoßpunkten von Versetzungen auch andere Wachstumsstrukturen sichtbar machen, wurden ermittelt. Die durch selektive Ätzung erhaltenen und die allgemein auftretenden Ätzfiguren wurden mit den beobachtbaren Wachstumsstrukturen im polarisiertem Licht oder nach Bestrahlung mit Röntgen‐ oder γ‐Strahlen verglichen und Wachstumshypothesen zugeordnet.
Strukturelle Deutung der Hochdrucktransformationen der Zink‐ und Cadmiumchalkogenide
Authors: Bautsch H.‐J. , Däweritz L.
Published: July 2007

Die bei Normaldruck in der Sphalerit‐ bzw. Wurtzitstruktur kristallisierenden Zn‐und Cd‐Chalkogenide gehen unter hohem Druck in die NaCl‐Struktur über. Die im Vergleich zu den Zn‐Chalkogeniden wesentlich niedrigeren Transformationsdrücke der Cd‐Chalkogenide lassen sich auf Grund der Radienquotienten erklären. Analog der Abhängigkeit der Stabilität der Sphalerit‐ bzw. Wurtzitstruktur von der Größe des u‐Wertes kann eine Beziehung zwischen den Transformationsdrücken und den nach einer Näherungsformel berechneten u‐Werten aufgezeigt werden.
Zu einigen Eigenschaften des polaren Gadoliniummolybdats (I) Optische Untersuchungen zum Umschaltverhalten
Authors: Kürsten H. D. , Bohm J. , Scheiding C. , Blumberg H.
Published: July 2007

Es wurde das Verhalten der Domänen in ferroelektrischem GMO während des Umschaltens mittels eines elektrischen Feldes sowie mittels einachsigen Druckes zwischen Raumtemperatur und 160 °C untersucht. Die spezifischen Bewegungen der Domänenwände während des Umschaltens werden detailliert beschrieben. Außerdem wurde die elektrische Hysterese im Wechselfeld verfolgt.
Effect of crystal attrition on crystal size distribution in continuous crystallizers
Authors: Juzaszek P. , Kawecki W.
Published: July 2007

In a literature review is stated that the attempts to lessen the divergence between theory and practice of the determination of particle size distribution have not yet been successful. One of the significant causes of the observed deviations are abrasion and breakage. For this an effective growth rate re = rc + rs is postulated (rc – mean linear growth rate, rs – mean linear rate of size change by abrasion and breakage). Two models for the relation between these quantities are presented. – The dependence of attrition rate on particle size, especially in a CMSMPR crystallizer is discussed.
Epitaxial Deposition of GaAs in the Ga(CH3)3AsH3H2 System (III) Heteroepitaxy on Isolating Substrates
Authors: Petzke W.‐H. , Gottschalch V. , Butter E.
Published: July 2007

Epitaxial growth of GaAs has been achieved on CaF2, α‐Al2O3 and spinel substrates. X‐ray investigations showed well defined relations between layer perfection and the quality of substrate material. The formation of epitaxial layers in pyrolytic deposition processes is discussed in terms of supersaturation and its influence on nucleation and layer growth.
Spannungsfelder um Einzelversetzungen in anisotropen Medien
Authors: Unangst D. , Alter U.
Published: July 2007

Es wird eine Näherungslösung des Differentialgleichungssystems für die Verschiebungen um eine Einzelversetzung in anisotropen Medien angegeben. Die Bedingungen für den Gültigkeitsbereich der Näherung werden erläutert.
Realstrukturuntersuchungen an CaF2
Authors: Dressler L. , Dänhardt W.
Published: July 2007

Blockstrukturen von CaF2‐Kristallen werden mit der Röntgentopographie (Berg‐Barrett‐Technik) und der Zweikristalldiffraktometrie untersucht. Die Möglichkeiten dieser Techniken bei der Untersuchung von Proben mit Blockstrukturen werden diskutiert.
Study of the Electrophysical Properties of Lithium Metaniobate Single Crystals with Deliberately Introduced Dopants
Authors: Antonov V. A. , Arsenev P. A. , Baranov B. A. , Farshtendiker V. L.
Published: July 2007

The effect of the dopants Ti, V, Cr. Mn, Ni, Ho, Er, Tm deliberately introduced into the melt of Czochralski grown lithium niobate (LiNbO3) crystals on their electrophysical properties — electric conductivity, dielectric permittivity and loss tangent — has been studied.

The characteristics were measured at temperatures up to 1200°C. The mechanism of dopant introduction into the crystalline lattice and the nature of electric conductivity of LiNbO3 at varius temperatures are discussed.
Chemical Effects at the Deposition of Germanium onto Yttrium‐Iron‐Garnet Single Crystals
Authors: Wendt M. , Fischer K.
Published: July 2007

At the deposition of Ge onto YIG‐crystals by uhv‐evaporation a sharply limited temperature Tst was found with no further deposition above this point. Several experimental facts suggest the following model: incoming Ge atoms pick out oxygen atoms from the substrate and reevaporate as GeO. The step temperature Tst is defined by an equilibrium of the incoming Ge vapour rate, rGe, and the GeO evaporation rate. For rGe = 3 monolayers/sec we found Tst = 510°C.
Dielectric Properties of Triglycine Fluoberyllate Depending on the Conditions of Growing
Authors: Tsedrik M. S. , Margolin L. N.
Published: July 2007

The paper deals with the influence of Triglycine Fluoberyllate (TGFB) monocrystals growing conditions upon the dielectric permeability ϵ and dielectric loss angle tangent tg δ in wak and strong electric fields. A temperature hysteresis of the dielectric permeability is to be observed. The Curie‐temperature, the Curie‐Weiss constant, the tangent of inclination angle of 1/ϵ function depending upon the temperature in ferroelectric and paraelectric regions and the values characterizing the nonlinearity of TGFB monocrystals were determined proceeding from the conditions of growing.
Morphological and X‐ray study of SiC crystals grown from gas phase
Authors: Chojnacki J. , Oleksyn B. , Stobierski L.
Published: July 2007

SiC crystals obtained from the gas phase were investigated in order to characterize their morphology and polytypic modifications. Specific X‐ray patterns showed the occurrence of one‐dimensional disorder in some of α‐SiC crystals.
Effect of different barium concentrations in KCl crystals on X‐ray diffuse scattering
Authors: Braude I. S. , Rogozyanskaya L. M. , Startsev V. I.
Published: July 2007

Using the X‐ray diffuse scattering technique, KCl crystals with various Ba impurity concentrations (0.0027–0.353 at. %) have been studied. Isointensity curves for all the crystals studied were constructed, which permitted discovering a strong concentration dependence of the diffuse scattering intensity. Starting with 0.0027 at. % Ba the Guinier‐Preston zones appear in the {100} planes. At higher Ba concentrations their number (up to 7 planes in the zone) and sizes increase.

The limiting Ba solubility in the KCl lattice is shown to be less than 0.0025 at. %. The diffuse spot elongation in the 〈130〉 directions at Ba concentration of 0.012 at. % results from diffraction effects of summation of spaces stress vectors acting in the 〈100〉 direction. The analysis of non‐uniform Ba distribution in KCl gave the form and character of segregates which are described by a two‐phase model. Shown is the effect of various impurity concentrations on the coherent coupling of the substance and matrix.
Strukturelle Umklapp‐Vorgänge in metastabilen β1‐Kupfer‐Zink‐Mischkristallen bei tiefen und höheren Temperaturen (I). Gitterdynamische Skizze1)
Authors: Kunze G.
Published: July 2007

Die absolute Größe des Schubmoduls G′ = (c11 – c12)/2 stellt ein Maß für die Wahrscheinlichkeit dar, daß in metastabilen β1‐Cu‐Zn‐Mischkristallen strukturelle Umklappvorgänge eintreten. Sie treten ein, wenn G′ einen kritischen Wert G′krit. unterschreitet, was entweder durch Erniedrigung der Temperatur T oder/und der Zn‐Konzentration x bewirkt werden kann. Im ersten Fall sinkt der Fermi‐, im zweiten Fall dieser und außerdem der Coulomb‐Beitrag zu G′(T, x). Beide Beiträge stabilisieren das β1‐Gitter und sind daher spezifisch für dessen gitterdynamisches Verhalten, insbesondere auch im Bereich langwelliger, thermoakustischer Gitterschwingungen, aus denen heraus sich die kooperative Umklapp‐Bewegung entwickelt.

Günstig orientierte Versetzungen können die Umklappung mit auslösen helfen oder auch auslösen, wenn sich der Schubmodul G′ in ihrer Umgebung dem Wert G′krit nähert. Bei isothermen Reaktionen ist dies in jenen β1‐Bereichen der Fall, deren Zn‐Konzentration x zugunsten der anderer Bereiche absinkt und dabei die Umklappkonzentration xMs erreicht, da G′krit = G′(xMs) ist. Voraussetzung dafür ist eine diffusionsähnliche Heterogenisierung der β1‐Matrix in sog. β‐ und β‐Bereiche (Vordiffusion über Abschreckleerstellen), unter denen die letzteren sich mit Zn anreichern und unter Wahrung der Kohärenz mit den ersteren ihren Stabilitätsgrad erhöhen. Beiderlei Bereiche bilden zusammen ein sog. β/β‐Parkett, dessen Bausteine in isothermen Reaktionen bei höheren Temperaturen groß genug werden, d. h. eine kritische Größe erreichen, die Voraussetzung dafür ist, daß thermoakustische Scherungswellen genügend große Atomkollektive zum Umklappen bewegen und diesen zu neuen Gleichgewichtslagen verhelfen können (Vergleich mit einer sin‐Welle, die zu einer Zickzacklinie wird). Die Umklappung spielt sich nur in den zwischen den stabilen β‐Bausteinen liegenden β‐Bausteinen ab, die dabei in ein Übergangsgitter (β2) übergehen, das dem Tieftemperaturmartensitgitter β″ sehr ähnlich ist. Aus β2 entspringt das Gitter der α‐Phase.

Der Weg von β1 zu α ist daher durch folgende Schritte gekennzeichnet: Vordiffusion, (Umklappung + Versetzungsdissoziation), die zu β2 führen, und eine weitere Versetzungsdissoziation, die in den Gleichgewichtslagen des α‐Gitters mündet. Dieser Mechanismus fungiert als Keimbildungsmechanismus der α‐Phase. Nach Bildung ihrer Keime wachsen diese auf Kosten des (zuviel gebildeten) β (Nachdiffusion).

Bei zu niedrigen Temperaturen führen isotherme Reaktionen zu einer Miniheterogenisierung der β1‐Matrix, d. h. einem Zustand, der dem der Kaltaushärtung anderer Legierungen wahrscheinlich sehr ähnlich ist (Guinier‐Preston‐Zonen). Eine in dieser Weise miniheterogenisierte β1‐Matrix ist nicht umklappfähig, so daß sich keine α‐Kriställchen bilden können – es sei denn nach Wiederauflösung der Miniheterogenitäten durch Erhöhung der Reaktionstemperatur.
Spirals on flux‐grown plates of CaWO4
Authors: Patel A. R. , Arora S. K.
Published: July 2007

Thin and transparant single crystalline plates of calcium tungstate have been grown by using the method of isothermal flux evaporation at 840°C. The floating plates exhibited spiral depression on their top as‐grown surfaces as revealed by high resolution (20 A°) electron‐optical plant. It is believed that the spiral pattern results from thermal etching at the sites of helical dislocations.
Preparation and electric conductivity of V2O5 single crystals
Authors: Růžička M. , Hartmanová M. , Besedičová Š.
Published: July 2007

Present paper deals with the preparation of V2O5 single crystals, both pure and doped with Mg, Mn, and Fe respectively, by the method of zone melting. To verify the quality of crystals, measurements of electric conductivity were carried out in the direction perpendicular to cleavage plane (010). The results have shown that the prepared crystals are suitable for further investigation of physical properties.
Zur Realstruktur bearbeiteter Silizium‐Einkristallscheiben
Authors: Baehr Renate
Published: July 2007

Ausgangsmaterial für die Herstellung von Halbleiterbauelementen sind einkristalline Silizium‐Scheiben, die mit den Verfahren Trennschleifen, Läppen und Polieren bearbeitet werden. – Durch elektronenmikroskopische Abbildung der Silizium‐Oberfläche nach den entsprechenden Bearbeitungsschritten und TEM‐Untersuchungen nach einem zusätzlichen Tempervorgang werden Zusammenhänge zwischen Oberflächenstruktur und Versetzungsausbildung gesucht.
Der Einfluß kleiner Kohlenstoff‐ und Iridium‐Gehalte auf die Versetzungssubstruktur in Molybdän‐Einkristallen
Authors: Balan V. Z. , Barthel J. , Göbel R. , Jurisch M. , Matvienko L. F. , Ovsienko D. E. , Sosnina E. J.
Published: July 2007

Es wurde der Einfluß der Züchtungsbedingungen und kleiner Kohlenstoffzusätze auf die Versetzungssubstruktur in Molybdän‐Einkristallen hoher Reinheit sowie der Zusammenhang zwischen dem Verteilungstyp von Iridium‐Verunreinigungen und der Substruktur dotierter Mo‐Einkristalle untersucht. Für die Untersuchungen wurden autoradiographische und röntgenographische Methoden angewendet. In der Arbeit wird gezeigt, daß Kohlenstoff die Perfektion der Einkristalle wesentlich verschlechtert. Im Falle der Ir‐dotierten Einkristalle spielt der Verteilungstyp der Beimengungen (B‐Kerne, A‐, B‐Streifen/Zellen) eine entscheidende Rolle.
Kinetics of sodium fluosilicate precipitation
Authors: Söhnel O.
Published: July 2007

The formation of Na2SiF6 by discontinuous precipitation of dilute H2SiF6 with a 40% excess of an aqueous solution of NaCl under various conditions was studied. The values of induction time, number of crystals formed, their final size and their habit were determined during precipitation from solutions, whose initial supersaturation was 2 < S < 11. At S < 7–8 the crystals were formed by heterogeneous nucleation, whereas at S ≳ 7–8 homogeneous nucleation mechanism began to prevail. Once formed, the Na2SiF6 crystals were growing according to the screw‐dislocation mechanism till they reached visible size; the corresponding values of kinetic order of nucleation and of the growth rate constant were g = 1.35 and kg = 4.32 × 10−8 cm2.05 sec−1 g−0.35, resp. The value of interfacial tension on the phase boundary Na2SiF6 crystal — saturated solution was determined (σ ∼ 52 erg/cm2). The resulting Na2SiF6 crystals conformed to log‐normal distribution irrespective of conditions of precipitation. The dependence of the final size of crystals on supersaturation exhibited a maximum at S ∼ 6. Crystals of Na2SiF6 had a hexagonal habit, which was near to a spherical form at lower supersaturations, while dendritic crystals were formed at higher supersaturations.
Untersuchungen zur Konzentration und Ausheilkinetik von Kristallbaufehlern in Metallen mit Hilfe der Positronenannihilation. Kurzer Abriß und Literaturübersicht
Authors: Dlubek G.
Published: July 2007

Es erfolgt eine kurze Darstellung der Grundlagen und der Anwendung der Positronenannihilation zur Untersuchung von Kristallbaufehlern in Metallen, die ergänzt wird durch eine thematisch gegliederte Übersicht über neuere Literatur.
Single crystal growth of La2(SO4)3 · 9 D2O
Authors: de Saja J. A. , de Saja A. , Pastor J. M. , Rull F.
Published: July 2007

Single crystals of La2(SO4)3 · 9 D2O were grown from saturated D2O solutions. According to X‐ray diffraction measurements, the crystals have a hexagonal structure with unit cell parameters a = 10.996 Å and c = 8.077 Å (space group C–P63/m). Several physical properties were also determined (density, refractive indices, dielectric constants, specific heat, coefficient of linear expansion, microhardness).
Strukturierung und Verhalten von AuGaSb‐Kontakten
Authors: Vogel Klaus K. , Engel Aribert
Published: July 2007

Der Einfluß der Herstellungsbedingungen von Au‐Kontakten auf ihre Struktur und das elektrische Verhalten wurde an p‐ und n‐GaSb untersucht. Die nach Czochralski gezogenen GaSb‐Proben haben (111)‐Orientierung und sind mit p = 2–5 · 1017 cm−3 eigenleitend bzw. mit n = 4–8 · 1017cm−3 Te‐dotiert. Besonders wurde der Einfluß verschiedener Nachbehandlungstemperaturen zwischen 20°C und 400°C auf die Kontakteigenschaften studiert. An den hergestellten Au‐Kontakten erfolgten Widerstandsmessungen nach der Vierspitzenmethode. Es wurde eine Änderung des Kontaktwiderstandes in Abhängigkeit von der Nachbehandlungstemperatur und vom eingesetzten Drahtkontaktierverfahren festgestellt.
Funktionelle Abhängigkeiten der Gleichgewichtsverteilungskoeffizienten in Molybdän
Authors: Duží Pavel
Published: July 2007

Aus einer genaueren Untersuchung der Periodizität der Gleichgewichtsverteilungskoeffizienten in Molybdän geht hervor, daß die ko‐Werte der Beimengungen in Mo von drei Haupteinflußfaktoren abhängen vom a) Valenzfaktor (Anzahl der Valenzelektronen), b) Größenfaktor (Differenz der Atomradien von Mo und Beimengung), c) Gitterstabilitätsfaktor (die wirklichen oder hypotetischen Schmelzpunkte TM des mit Hauptmetall identischen Gitters des Fremdelementes). Nach dieser Abhängigkeit können die kc‐Werte der Beimengungen, für die keine oder ungenaue Zustandsdiagramme mit Mo vorliegen, vorhersagt oder prezisiert werden.
Gitterkonstantenänderungen und chemische Inhomogenitäten von tetragonalem ZnSiP2
Authors: Günther F. , Oettel H. , Stündl P. , Heide G.
Published: July 2007

Lokale Gitterkonstantenänderungen in ZnSiP2‐Kristallen, die mit Hilfe der Bond‐Methode nachgewiesen wurden, belegen örtliche chemische Inhomogenitäten, die mit Si‐Konzentrationsänderungen bis zu etwa 0,8 At.‐% erklärt werden können.
Zur Versetzungsdichtemessung von GaAs‐Einkristallen mit dem automatischen Gefügeanalysator EPIQUANT
Authors: Richter H.
Published: July 2007

Der Einfluß der EPIQUANT‐Einstellgrößen auf die Meßgenauigkeit der Versetzungsdichte der GaAs‐>100<‐Kristalle wird beschrieben und eine Methode zur Bestimmung der mittleren Größe der Versetzungsätzgruben aus der Schnittlängenklassierung dargelegt. Spezielle linearanalytische Messungen zur Anordnung der Versetzungen auf dem Kristallquerschnitt und zur Größenverteilung der Versetzungsätzgruben ergeben wertvolle Hinweise auf die Perfektion des Einkristalls.
Morphologische Untersuchung von synthetischen Diamanten
Authors: Vavrda Josef
Published: July 2007

Mittels Röntgenstrahlbeugung wurde die Desorientierung der Subkörner von Diamantkristalliten untersucht. Der Zusammenhang zwischen der Ausscheidung von Katalysator‐Begleitphasen, Desorientierung von Subkörnern und Zwillingsbildung bzw. Aggregation von Diamantkristalliten wurde festgestellt.
Diffraktometrische Substrukturanalyse
Authors: Oettel H.
Published: July 2007

Starting from the work of WARREN about the influence of grain size on intensity fluctuations of X‐ray interferences simple relations between these fluctuations and substructure parameters as subgrain size and desorientation are derived. As can be shown measurements with different beam divergencies allow to estimate subgrain size and desorientation separately. Combined X‐ray and TEM investigations on deformed and annealed armco‐iron show the usefulness of the proposed method of diffractometrical substructure analysis.
Optimierung der quantitativen röntgenographischen Phasenanalyse
Authors: Fiala Jaroslav
Published: July 2007

Es wird ein neues Verfahren der absoluten quantitativen röntgenographischen Phasenanalyse auf der Basis der quadratischen Programmierung beschrieben, das optimale analytische Resultat garantiert. Die theoretischen Schlußfolgerungen werden durch ein praktisches Beispiel illustriert.
The defect structure of CdS crystals heavy doped with Cu, Se. and Zn atoms
Authors: Bak J. , Demianiuk M. , Żrmija J.
Published: July 2007

In this paper the defect structure of CdS crystals doped with Cu, Se and Zn atoms has been investigated. There were used two X‐ray methods: the oscillating slit and oscillating film methods. CdS crystals were obtained from the melt under pressure of Se and Zn 0.5, 0.75, 1% wt and Cu 0.25, 0.5, 0.75, 1% wt in relation to CdS crystals. It was proved that high doping damages the structure of CdS crystals and that especially Cu impurity much more disturbs the crystal lattice than Zn one. Se atoms cause rather small deformation of crystal and increase the lattice constant, this being connected with decreasing of energy gap.
Die Phasenübergänge und die Störstellenphotoleitung von Sb2S3
Authors: Grigas J. , Urbonawitschius W. , Orliukas A.
Published: July 2007

Es wird die Abhängigkeit der Dielektrizitätskonstante und Photoleitfähigkeit von Sb2S3‐Kristallen von den Züchtungsbedingungen dargestellt. Es wird gezeigt, daß an Kristallen mit einer hohen Dielektrizitätskonstante, die spontane Polarisation aufweisen, auf der ferroelektrischen Fläche eine Störstellenphotoleitung beobachtet wird.
The thermal decomposition of aluminium hydroxide doped with Fe(III) ions
Authors: van Dijk J.
Published: July 2007

The thermal decomposition of various aluminium hydroxides doped with Fe(III) ions has been studied using ESR. The transition aluminas (η, γ, ϰ‐Al2O3) formed at low calcination temperatures show the ESR‐spectrum characteristic for Fe(III) ions incorporated in low crystalline materials. Spectra of doped reference compounds (ZnAl2O4, MgAl2O4, (dis)ordered LiAl5O8) showed that disorder in the cation sublattice could be responsible for this feature. The ESR spectra of aluminas (θ, x, α‐Al2O3) formed at high calcination temperatures reveal well‐defined and characteristic fine structures. Comparison with reference compounds (β‐Ga2O3, α‐Ga2O3) allows to draw conclusions as to the structure. The quality of the spectrum of δ‐Al2O3 formed in the dehydration sequence of boehmite, was in between that of the low and high temperature aluminas. In order to explain some of the features observed in the various dehydration sequences, a discussion based on the coordination of the anions along lines pointed out by GORTER, has been put forward. To this end, the regularity of the anion coordination is followed within the special packing sequences of the anion layers in the dehydration products.
Untersuchung dünner Isolatorschichten in Sandwich‐Anordnungen mit dem Elektronenspiegel‐Mikroskop
Authors: Heydenreich J. , Godehardt R. , Vester J.
Published: July 2007

Es werden bei Elektronenspiegel‐Untersuchungen von Au–SiOx–Ge‐Sandwich‐Systemen beobachtete charakteristische Bildstrukturen beschrieben, die durch Leitfähigkeitsinhomogenitäten in der Isolatorschicht hervorgerufen werden. Durch eine quantitative Auswertung der experimentellen Ergebnisse ist eine Abschätzung der Ausdehnung und der Stärke der Inhomogenitäten möglich.
Computer generation of composite X‐ray powder patterns. A BESM‐6 FORTRAN program and its application to special problems of quantitative phase analysis
Authors: Fichtner‐Schmittler H. , Fichtner K.
Published: July 2007

A computer program for the calculation and schematic representation of X‐ray diagrams of a polycrystalline substance or mixture of substances is outlined. The generation of X‐ray powder patterns is based on input data characterizing the crystal structures (lattice constants, atomic positions, etc.) and the features of the diagrams (diffractometer or Guinier type; line shape, resolution). Three examples illustrating the application of the program are discussed.
α‐substituted Phosphoryl Compounds (II). The Crystal and Molecular Structure of Diphenyl‐[5,6‐dichloro‐1, 3‐benzodioxol‐(2)]‐phosphine‐oxide, C19H13O3PCl2
Authors: Kulpe S. , Seidel I.
Published: July 2007

The compound crystallizes in the monoclinic space group P 21/c with four molecules per unit cell, and with the lattice parameters a = 11.807 Å, b = 13.070 Å, c = 11.312 Å, β = 96.74°. With X‐ray diffraction data collected on a four circle diffractometer, the crystal structure has been determined by direct methods and refined to an R‐value of 0.061 for 2735 measured and symmetrically independent reflections. The substance is a derivative of acetales of formyl diphenyl phosphine oxides. Correlations between the geometry of the structure and NMR‐data are of interest.
Crystal and Molecular Structure of Piperidinium‐acet‐m‐Cl‐anilide‐chloride
Authors: Reck G. , Leibnitz P.
Published: July 2007

Piperidinium‐acet‐m‐Cl‐anilide‐chloride crystallizes in the orthorhombic space group Pca21 with 4 formula units C13H18ON2Cl2 in the unit cell. The lattice parameters are a = 10.348 Å, b = 12.280 Å and c = 11.335 Å. The crystal structure was determined by the heavy atom method and refined by least‐squares procedures to the conventional R = 0.045. Bond lengths, bond angles and the conformation of the drug molecule were determined. Cl− ions are linked to the molecules by hydrogen bonds forming chains together with iones and molecules related by the a‐glide plane.
Structural Properties of S‐alkylated Dithiolene Chelates (II). Crystal and Molecular Structure of Tris‐(S‐methylethene‐1,2‐dithiolato)cobalt
Authors: Richter R. , Sieler J. , Kaiser J.
Published: July 2007

The crystal and molecular structure of tris(S‐methyl‐ethene‐1,2‐dithiolato)cobalt has been determined by X‐ray structure analysis. The substance crystallizes in the cubic space group Pa3 with a = 14.545 Å and 8 formula units per unit cell. The structure was solved by heavy‐atom technique and refined to a final R value of R = 0.11. The co‐ordination polyhedron of this trischelate is a slightly distorted octahedron. The distances from the cobalt atom to thioether‐sulphur atoms and to mercaptide‐sulphur atoms differ significantly. The methyl groups are arranged in a facial (cis) manner. The molecule has the symmetry C3. The substance shows great structural similarity to anionic tris(dithiolene) chelates.
Interdiffusion in FCC Ni‐in alloys
Authors: Budurov S. J. , Boshinov W. S. , Kovatchev P. D.
Published: July 2007

It is the purpose of this study to add direct diffusion data to the results obtained from the cellular precipitation kinetics in earlier papers (BUDUROV et al.) The values of the interdiffusion coefficients were determined in the temperature range from 900° to 1100°C, using conventional diffusion couples and an electron microprobe.
The kinetics of crystal growth of succinonitrile and cyclohexanol from the melt
Authors: Alfintsev G. A. , Chemerinsky G. P. , Fedorov O. P.
Published: July 2007

The crystal growth kinetics of two organic substances with low melting entropies — succinonitrile and cyclohexanol — was studied in the wide range of supercoolings. The values of kinetic coefficients which connect growth velocity and interface supercooling are equal to 0.17 – 0.72 m/(s · K) for succinonitrile and (1.6 – 2.0) · 10−4 m/(s · K) for cyclohexanol. Viscosity of these substances was measured to compare the experimental data with theoretical dependences for continuous growth. It has been found that experimental kinetics of substances under study differs significantly from the expression of Wilson‐Frenkel type.
Treatment of data on metastable zone width leading to nucleation characteristics and measurements in the system potassium dichromate‐water
Authors: Nývlt J.
Published: July 2007

Measurements of the width of metastable zone can be used for characterisation of the kinetics of nucleation. Methods of treatment these data discussed in literature are summarised, re‐examined and arranged in order to enable smoothing of experimental data and simultaneous calculation of the values of certain characteristic nucleation parameters. An example (potassium dichromate in aqueous solution) shows that the values obtained in this way are within usual limits given in the literature. The results indicate that in unseeded solutions the nucleation was probably heterogeneous one, whereas in presence of a fixed seed an adsorbed layer mechanism of secondary nucleation followed by a fluid shear action seems to explain the results.
Growth and characterization of SSD InP crystals used as substrates for infra‐red LED's
Authors: Moravec F. , Novotný J. , Janáček J.
Published: July 2007

Bulk indium phosphide crystals have been grown by the synthesis, solute diffusion (SSD) method. Various growth temperatures and temperature gradients in the indium melt were investigated. The growth temperature of about 850–900°C and the temperature gradient of about 10–15°C cm−1 were found as the most suitable growth conditions. All grown crystals were of the n‐type either undoped or doped with Te or Sn. Infrared light‐emitting junctions were grown by single LPE process. Characteristic surface structures of InP epitaxial layers as a function of the growth temperature and cooling rate were observed. Efficiencies of LED's have been typically 0.8%. Single LPE process on LEC InP substrates has given LED's with substantially lower efficiencies.
Nucleation in quiet supersaturated ADP solutions
Authors: Nagalingam S. , Vasudevan S. , Ramasamy P. , Laddha G. S.
Published: July 2007

The nucleation study has been made with supersaturated ADP solution. Rate of nucleation as indicated by the induction period was measured for non‐agitated system over the temperature range 20°C–45°C. The nucleation rate increases with increase in temperature but supersaturation has the dominant effect as predicted by classical nucleation theory. However, attempts to analyse the results in accordance with classical theory were not entirely successful, but it is shown how the assumption of (a) a variation of crystal surface energy with temperature and (b) the influence of heterogeneous nucleation can account for the discrepancies. Activation energies, surface free energies and sizes of crystal nuclei were determined for nuclei of ammonium dihydrogen orthophosphate over the range of temperature 20°C–45°C.
Effect of γ‐irradiation on the lattice parameter and colour centre concentration in pure Ca2+, Sr2+ and Eu2+ doped KCI crystals
Authors: Damm J. Z. , Stepień‐Damm J.
Published: July 2007

The changes of lattice parameter and colour centre concentration are examined in KCI crystals (both pure and Me2+‐doped) irradiated by γ‐rays at room temperature. For the pure crystals the relative volume change vs. F‐centre concentration plot reveals the presence of two stages, one ascribed to the introduction of colour centre pairs (or F centres only) and other to the generation of the new dislocations (or new dislocations with trapped‐hole centres). In Me2+ doped crystals the lattice expansion bears a complex character (in the initial irradiation stage a transient maximum appears). Additional anomaly appears in Eu2+ KCI in the high‐dose range where in spite of a distinct F‐centre concentration drop a marked raise of the lattice parameter is observed.
Effect of some Me2+ impurity ions on the lattice parameter of KCI crystals
Authors: Stepień‐Damm J. , Łukaszewicz K.
Published: July 2007

The effect of concentration of substitutional Ca2+, Sr2+, Ba2+ and Pb2+ ions on the lattice parameter of KCI crystals is examined. The amount of lattice contraction induced by the alcaline earths ions qualitatively correlates with the pertinent ionic radii values (relative unit cell contraction induced by one impurity dipole amounts to −0.905, −0.110 and −0.020 for Ca2+, Sr2+ and Ba2+ ions, respectively). The initial drop of lattice parameter observed at low Me2+ concentration is tentatively ascribed to the drop of dislocation density. In Pb2+ doped crystals except for the above initial drop, at higher dopant concentration no effect upon the lattice parameter is found.
Phase diagram and single crystal growth of the CuInSe2xS2(1−x) solid solutions
Authors: Bodnar I. V. , Bologa A. P. , Korzun B. V.
Published: July 2007

The phase diagram of the CuInSe2‐CuInS2 system is plotted using DTA and the solidus and liquidus lines by the approximation of the theory of regular and ideal solutions are calculated. The single crystals of the CuInSe2xS2(1−x) solid solutions are first grown by chemical transport.
Dislocation microwave electrical conductivity of semiconductors and electron‐dislocation spectrum
Authors: Ossipyan Yu. A.
Published: July 2007

The experimental data are presented on the microwave electrical conductivity of dislocated silicon and germanium as well as on the effect of light on the dislocation ESR signal. Based on the results obtained the new scheme of dislocation electron energy spectrum is suggested.
Character of indirect exchange interactions in lanthanum manganite
Authors: Karavay A. P. , Sirota N. N. , Pavlov V. I.
Published: July 2007

Using the neutron diffraction and magnetic studies a model for exchange interactions in lanthanum manganite with altering ranges having antiferromagnetic and ferromagnetic ordering in the crystal structure is suggested. The anisotropic exchange interaction of the Mn3+ O2− Mn3+ type, accompanied by the local Jahn‐Teller oxygen octahedron distortions, dominates in antiferromagnetic ranges, while in the ferromagnetic ones there are two types of positive exchange interactions: Mn3+ O2− Mn4+, the mechanism of which has been proposed by Zener, and Mn3+ O2− Mn3+ without the local Jahn‐Teller distortions.
An experiment to evaluate methods for estimating fossil fuel resources
Authors: Sterman John D. , Richardson George P.
Published: July 2007

Estimates of petroleum and natural gas resources vary substantially, both over time and across estimation methods. This paper develops a simulation model of global oil resources to evaluate different resource estimation techniques. Protocols for the Hubbert life cycle and USGS geological analogy methods are developed and applied to synthetic data generated by the model. It is shown that the Hubbert method can generate an accurate estimate as early as twenty years before the peak of global production, but the geological analogy approach overestimates the true resource base over the life cycle of the resource. The results show the applicability of simulation and the synthetic data approach to the problem of evaluating forecasting methods.
Forecasting capacity and capacity utilization in the U.S. aerospace industry
Authors: Greer Wlllls R. , Liao Shu S.
Published: July 2007

The forecasting of capacity and its utilization is particularly relevant in the aerospace industry because of long product delivery lead‐times and the forward‐pricing system. The objective of this paper is to develop a method for forecasting both the industry's capacity and its capacity utilization so that decision makers who must rely on this information may have policy guidance. The result shows that the aerospace industry's capacity expansion rate is closely tied to its present and recent past state of capacity utilization, and to anticipated changes in output. Output, in turn, can be predicted by using Five Year Defense Plans data and information on the cyclical nature of commercial business. Based on these findings, we were able to build an accurate model for forecasting aerospace industry capacity utilization.
Bushfire rate‐of‐spread forecasting: Deterministic and statistical approaches to fire modelling
Authors: Beer T.
Published: July 2007

The three basic modelling approaches used to explain forest fire behaviour are theoretically, laboratory or empirically based. Results of all three approaches are reviewed, but it is noted that only the laboratory‐ and empirically based models have led to forecasting techniques that are in widespread use. These are the Rothermel model and the McArthur meters, respectively. Field tests designed to test the performance of these operational models were carried out in tropical grasslands. A preliminary analysis indicated that the Rothermel model overpredicted spread rates while the McArthur model underpredicted. To improve the forecast of bushfire rate of spread available to operational firefighting crews it is suggested that a time‐variable parameter (TYP) recursive least squares algorithm can be used to assign weights to the respective models, with the weights recursively updated as information on fire‐front location becomes available. Results of this methodology when applied to US Grasslands fire experiment data indicate that the quality of the input combined with a priori knowledge of the performance of the candidate models plays an important role in the performance of the TVP algorithm. With high‐quality input data, the Rothermel model on its own outperformed the TVP algorithm, but with slightly inferior data both approaches were comparable. Though the use of all available data in a multiple linear regression produces a lower sum of squared errors than the recursive, time‐variable weighting approach, or that of any single model, the uncertainties of data input and consequent changes in weighting coefficients during operational conditions suggest the use of the TVP algorithm approach.
Predicting turning points in business cycles by detection of slope changes in the leading composite index
Authors: Jun Duk Bin , Joo Young Jin
Published: July 2007

A Bayesian statistical method to detect turning points in the leading composite index is introduced. Under the assumption of causal priority of the leading composite index to the business cycle, the turning points in business cycles are predicted by detection of them in the index. The underlying process of the leading composite index is described by a dynamic linear model with random level and slope, where the random slope is distorted by a random shock at each turning point. The turning point is detected by obtaining a large value of the posterior probability that one of the previous slope components has undergone a major change. The intensity of the change causing a turn in the business cycle is quantified by estimating the size of the random shock. The application of the results to the US leading composite index are compared with results of earlier studies.
On scoring asymmetric periodic probability models of turning‐point forecasts
Authors: Ghysels Eric
Published: July 2007

To forecast the turnaround of an economy we do not usually take seasonal effects into account. Recently, the author showed that business cycle turning points as well as durations do not appear to be uniformly distributed throughout the year (see Ghysels, 1991a). In this paper we suggest improving the forecasting performance of turning‐point predictions by adopting periodic hazard models. Following Diebold and Rudebusch (1989), we construct several formal probability models and score their prediction performance. The results indicate that for sequential forecasting rules significant gains can be made by exploiting periodicities in turning‐point probabilities.
Virtual work space for assembly
Authors: Hirata Yukihiro , Mizuguchi Takehisa , Sato Makoto , Kawarada Hiroshi
Published: July 2007

To implement a human interface for efficiently modeling 3‐D shapes on a computer, a virtual works space enabling direct manipulation of a shape model on a computer similar to manipulating a real 3‐D object must be constructed. In this virtual work space, the tactile and force sensations arising while the object is manipulated must be fed back to the person. We previously proposed the space interface device SPIDAR capable of force feedback to the person's fingertips. However, only one finger could be used in SPIDAR, so operations where the object is held were not possible. In this paper, we extend SPIDAR and propose the space interface device SPIDAR II to implement a virtual work space where operations involving holding and moving objects are possible. This device measures the position of the minimum of the two fingers needed to manipulate objects and can provide tactile feedback to the fingertips while an object is being held. A prototype device is built and a virtual work space is constructed where holding and moving objects is possible. Further, an experiment is conducted to investigate the effect of tactile feedback to work operability in this virtual work space, and its effectiveness is confirmed.
A method of anaphora resolution based on the concept of observation
Authors: Yamamura Tsuyoshi , Ohnishi Noboru , Sugie Noboru
Published: July 2007

The meaning of a sentence depends on the context in which it is used with other sentences. This results from the fact that several sentences are usually integrated to form a context. To date, the study of context structure has been concerned mostly with the semantic relation between the verbs (predicates) of the two sentences. It should be noted, however, that even if the verbs are semantically related, the relation may be felt to be unnatural and cannot be considered to form a context when the relation called discourse factor, such as the relationship between viewpoint, is not established. This study considers the context construction problem from the viewpoint of the natural relation between sentences. For this purpose, the concept of observation is introduced, this is an extension of viewpoint. Using that concept, it is shown how the interpretation of the sentence is helped by the preceding sentence. Then, the application to the resolution of anaphora is discussed. In other words, the anaphora is resolved by establishing the natural relation between sentences. It is shown that the anaphora problem which has not been resolved by the past method can now be resolved. The effectiveness of the anaphora resolution considered in this study is verified by examining actual examples.