bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of Chemical and Mechanical Properties of Double Base Propellants during Aging
Authors: Volk F. , Bohn M. A. , Wunsch G.
Published: December 2004

Thermal and mechanical stability of rocket and gun propellants are very important properties with regard to safety during storage and handling and to the interior ballistics behavior during combustion.

However, our knowledge of how these properties are connected is poor. In order to better understand the aging behavior of double base propellants, the following properties were measured between 60 °C and 90 °C: the depletion of the stabilizers, the degradation of the molecular weights of nitrocellulose and the decrease of the mechanical properties (tensile strength and strain at break).

The evaluation of the kinetic parameters of the different aging processes mentioned has shown that stabilizer depletion, molecular weight degradation of nitrocellulose and decrease of mechanical properties must be closely connected.
Investigation of the Combustion of Liquid Gun Propellants in Closed Chambers
Authors: Klingenberg G. , Knapton J. D. , Watson C.
Published: December 2004

Closed chamber tests on hydroxylammonium nitrate (HAN) based liquid monopropellants (LPs) were performed at loading densities of about 0.2 g/cm3 at both the Fraunhofer‐Institut für Kurzzeitdynamik (EMI‐AFB), and the Ballistic Research Laboratory (BRL). The objective of the studies was to investigate the decomposition of the HAN based liquid propellants under various conditions. Pressure and temperatures were measured for both neat and intentionally contaminated monopropellants. Contaminants tested were iron, copper, aluminum, and nickel at concentrations of about 100 ppm. The temperatures were determined using both thermocouples and specially designed temperature (emission) gages. The data illustrate the behavior of the liquid propellants during the decomposition phase.
Burning Behavior of Composite Solid Propellant containing porous ammonium perchlorate
Authors: Leu An‐Lu , Yeh Tsao‐Fa , Chang Fang‐Mo , Liu Chao‐Shih , Huang Chen‐Chia , Liu Fang , Shih Yu‐San
Published: December 2004

A pilot scale fluidized bed process was developed for preparing porous ammonium perchlorate (PAP) in various particle sizes. The oxidizer, ammonium perchlorate (AP), of composite solid propellant was partially replaced by PAP which was obtained by the fluidization process. The burning rate of propellants containing PAP was found to increase as compared with that of propellants without PAP. In the present study, the effects of percentage content and particle size of PAP incorporated in propellant compositions, on the burning rate were investigated. The results showed that the burning rate increases with increasing of PAP content and with decreasing of PAP particle size for trimodal oxidizer propellants.
Combustion of Gas‐Permeable Porous Systems
Authors: Frolov Yu. V. , Korostelev V. G.
Published: December 2004

The process of combustion of gas‐permeable porous systems when there is a pressure drop at the inlet into pores has been studied. The dynamics of processes during one‐dimensional and non‐dimensional combustions has been analyzed.

Conditions for stabilization of combustion rates are revealed. Analytical expressions are found to determine main parameters in combustion of gas‐permeable systems with non‐melting components and relatively narrow pores.
Evaluation of various stabilizers for Stability and Increased Life of CMDB Propellants
Authors: Asthana S. N. , Deshpande B. Y. , Singh H.
Published: December 2004

This study establishes superiority of resorcinol as stabilizer for CMDB propellants followed by RDME (resorcinol dimethylethcr) as compared to other resorcinol derivatives and that of CdO amongst metal oxides. The use of resorcinol and CdO combination in CMDB formulation results in higher E of 33 kca/mol and shelf life of 203 years as compared to E of 31 kcal/mol and life of 70–73 years for resorcinol or CdO based composition suggesting their synergistic stabilization effect. Results of the present investigation bring out that aging mechanism of CMDB involves cleavage of RO‐NO2 bond like DBP, however, AP‐based CMDB are strongly autocatalytic. Thus stabilizers used in DBP (Carbamite and 2‐NDPA) do not take care of CMDB propellant aging. Suitability of resorcinol may be explained on the basis of its activated aromatic ring for scavenging of oxides of nitrogen.
Kinetics of Dehydration of Guanidine Nitrate in H2SO4/HNO3/H2O ternary mixtures
Authors: Liu Tai‐Kang , Shyr Yan‐Nian , Ho Chan‐Yuan
Published: December 2004

A nitroguanidine process development study was performed by investigating the kinetics of dehydration of guanidine nitrate in 81% H2SO4/5% HNO3/14% H2O ternary mixtures. An irreversible second order apparent kinetic model lumping both dissolution resistance and chemical reaction resistance was obtained from analysis of the experimental data, and was used to predict the performance of the cascade CSTR and semi‐batch reactor under some feasible conditions. The predicted yields are in reasonably good agreement with the ones from experimental measurements. A reaction mechanism was proposed and was shown to reasonably elucidate the observed rate phenomena.
Research on the process of Detonation of Explosive Mixtures of the oxidizer fuel type containing aluminium powder
Authors: Maranda A.
Published: December 2004

The results are given from measurements of the critical diameter and detonation velocity of explosive mixtures containing aluminium powder and ammonium and guanidine nitrates. Physico chemical interpretation of the obtained results are given.
Combustion Aspects of Sodium Azide and its mixtures with potassium perchlorate and burning catalysts
Authors: Hasue Kazuo , Iwama Akira , Kazumi Takashi
Published: December 2004

Linear burning rate, thermal aualysis, temperature profile, flame structure and cryogenic burnability for the mixtures of sodium azide (SA) of different particle sizes (3.5 μm, 22 μm, and 67 μm), potassium perchlorate (KP) and with or without three kinds of burning catalysts (GeO2, Er2O3, and Y2O3) have been investigated. The linear burning rates increase with the KP content up to 33Wt% for similar SA particle size. The temperature‐time histories in the vicinity of burning surface were obtained with 20 μm Type K thermocouple embedded in a Strand. The burning surface temperaturres of neat SA and of the SA/KP mixtures are nearly 350°C and 350°C ∼ 550°C, respectively, while the existence of the decomposition surface at 250 °C and condensed layer was suggested with SA/KP mixtures. In visual observation for the flame structure, the front of luminous flame zone appers to be in contact with the condensed phase surface. For example, however, the temperature profile suggests that there exists finitc distance from decomposition surface to flame front in the order of 0.05 mm ∼ 0.1 mm at 1 MPa for SA/KP = 80/20. The differential thermal analysis indicates that the tested catalysts have retarding effect on SA combustion, but a positive effect on neat KP decomposition in spite of being impotent for the burning rate increase of the SA/KP mixture. It was also found that SA strands containing appropatiae fractions of KP can hurn even in liquid nitrogen.
New dependence of Activation Energies of Nitroesters Thermolysis and possibility of its application
Authors: Zeman Svatopluk
Published: December 2004

Relationship was found between activation energies E of low‐temperature non‐autocatalyzed thermolysis of the nitric acid esters, on the one hand and their oxygen balances OB100, on the other. By this relationship, molecular‐structural dependence is evidenced of values E, at the same time existence is signalized of the direct relationship between the values E and the impact sensitivity of nitroesters.
Numerical Simulation of Casting Explosives in Shell
Authors: Chen Chun‐Yu , Shiuan Jonq‐Hwa
Published: December 2004

Predicting interface position of solid‐liquid phase change is important for the filling of explosives in the shell. The cooling process of casting charge is discussed analytically and experimentally. The basic equations describing this process are derived from a modified and extended equivalent heat capacity model. Numerical calculations are then performed to determine the solidification front distributions and temperature distributions. The experiments are performed using TNT as the phase change material. Comparison between practical experiments and computer simulation has shown that there is a good agreement. By using computer calculations, a better knowledge of important parameters for the casting process can be easily obtained.
A Simple Model for Jet Formation in Shaped Charges
Authors: Jones David A.
Published: December 2004

A simple model capable of reproducing all of the experimental results known for the MRL 38 mm diameter shaped charge is described. The basis of this model is the original analytical work of F'ugh, Eichelberger and Rostoker and the more recent work of Hirsch, and of Carleone, Jameson and Chou. The three phenomenological constants required by the model are found by fitting to data from the BRL 105 mm diameter unconfined shaped charge. The model is then used to calculate the jet velocity gradient and the collapse angle versus time for the MRL standard charge. Good agreement has been found with recent experimental results.
The Equation of State of Detonation Products obtained from cylinder expansion test
Authors: Chen Chun‐Yu , Shiuan Jong‐Hwa , Lan I‐Feng
Published: December 2004

The equation of state of detonation products is essential to the explosive application. The study of this paper is set up with the following procedures: (1) cylinder expansion test is performed in a detonation test chamber, and the radial expansion, varied with time, of copper tube which is filled with Composition B, is recorded by Hamamatsu streak camera, (2) the JWL parameters are obtained by means of a simple mathematical analysis, and (3) the 2DL Code has been modified using JWL equation of state instead of HOM equation of state to study the behavior of the detonation gases. The results show that the JWL parameters of this study are in close agreement with the LLNL's approach and the JWL equation of state can more accurately predict the behavior of detonation products than the HOM.
Relationships between Electron Structures of N‐Methylolamines and their Reactivity in the mannich reaction
Authors: Zhang Yuejun , Dong Wei , Shi Jie , Li Weimin
Published: December 2004

The electron structures of various unstable N‐methylolamines and their imine cations formed during the urotropine nitrolysis process were studied by SCF‐CNDO/2 computation. The relative tendency of forming imine cations from such N‐methylolamine molecules was assessed by the computation values of Mulliken bond order (Mco) of CO bond and the negative values (−Eco) of two‐atome energy. The electrophilic order of imine cations described by the products (Zco) of carbocation's static charges and the rations of partition functions Qs/Qp between s and p electrons, were used to express the relative reactivity of the Mannich reaction intermediates. Experimental results were satisfactorily explained by the calculated values, and the reactivity of nitrolysis fragments was successfully predicted by the defined values.
The Influence of the Various Types of Binder on the burning characteristics of the magnesium‐, boron‐, and aluminum‐based igniters
Authors: Barišin Dubravka , Batinić‐Haberle Ines
Published: December 2004

The behaviour of six different types of binders phenol‐formaldehyde resin, shellac, polyvinylchloride, ethylcellulose, nitrocellulose, and fluorel was investigated in pyrotechnic compositions on the basis of magnesium, boron and aluminum. It has been found that the nature of the binder significantly influences the burning characteristics of the igniters. Correlation has been found between binder exothermicity and investigated characteristics. In addition, the influence of the contents of phenol‐formaldehyde resin and of fluorel, in the range of 0% to 25% on the same performance characteristics was studied. Phenol‐formaldehyde resin has been chosen as preferred binder for the investigated igniters in an amount of 5%.
Analysis of 2‐Nitrodiphenylamine and its Major Derivatives in double and triple base propellants
Authors: Kansas L. , Robertson D.
Published: December 2004

High performance liquid chromatography is used to separate 2‐nitrodiphenylamine and its major reaction products with nitrogen oxide in double and triple base rocket and artillery propellants. A reversed phase, isocratic technique is employed. Analysis of samples stored at ambient and elevated temperatures is discussed.
The Two‐Steps Reaction Zone Structure: A way to interpret non‐ideal detonations observations
Authors: Fauquignon C.
Published: December 2004

The reaction zone of an heterogeneous explosive is the sequence of micro‐thermal explosions followed by a volume combustion until the end of the reactions. It is shown that the physical and geometrical parameters characterizing the explosive play a different and frequently opposite role in the two steps of the reaction zone.
Studies on Burn Rate of Polyvinylnitrate and Effect of Modifiers
Authors: Mishra S. C. , Durgapal U. C. , Pant Jyotsna , Dutta P. K.
Published: December 2004

Burn rates of polyvinylnitrate (PVN) without and with addition of 1% by weight of ballistic modifiers, viz. carbon black, lead stearate, lead gallate and lead salicylate, have been determined at different pressures ranging form 10 kg/cm2 to 85 kg/cm2. The burn rate data show deviations from the standard ballistic equations r = a + bp and r = apn. Nearly plateau burning effect is shown, at lower pressure range, by gelatinized PVN, PVN + 1% lead stearate and PVN + 1% lead gallate, whereas mesa burning is shown by PVN + 1% lead gallate (at p = 40 – 50 kg/cm2) and PVN + 1% lead stearate (at p = 70 to 74 kg/cm2).
Tert‐Butylhydrazine as a Component of Mennich's Condensation
Authors: Mikşovský David , Vojtêch Aleş
Published: December 2004

A seven‐membered cyclic nitramine has been prepared from Mannich's condensation of ethylenedinitramine with formaldehyde and tert‐butylhydrazine.
Photoacoustic Spectroscopy of Some Energetic Materials
Authors: Hasue Kazuo , Nakahara Shoji , Morimoto Jun , Yamagami Tetsuo , Okamoto Yoichi , Miyakawa Toru
Published: December 2004

To find an effective laser source to ignite energetic materials, the absorption spectra of some energetic materials are obtained by means of a photoacoustic spectroscopy (PAS). In this experiment, PAS covers the wavelength region of 400 nm‐1600 nm in which no other conventional method can take absorption spectra for powdered energetic materials. Photoacoustic spectra of 18 energetic materials are reported. In general, energetic materials tested showed peaks in 600 nm–800 nm and 1400 nm–1600 nm ranges. It is found that the energy required to initiate explosives in the case of ruby laser initiation were correlated with their photoacoustic signal intensities.
A Diversity‐Oriented, Microwave‐Assisted Synthesis of 4‐oxo and 4‐chloropyrido[2,3‐d]pyrimidin‐7(8H)‐ones
Authors: Mont N. , Fernández‐Megido L. , Teixidó J. , Kappe C. O. , Borrell J. I.
Published: December 2004

A microwave‐assisted protocol for the synthesis of 4‐oxo and 4‐chloropyrido[2,3‐d]pyrimidin‐7(8H)‐ones, 13 and 9 respectively, bearing a carbon substituent at C2 and a chlorine atom at C4 is reported. The introduction of a wide range of substituents at C2 renders this methodology easily amenable to combinatorial chemistry applications. Two examples of further derivatization of compounds 9, substitution by amine and Suzuki coupling, under microwave irradiation are also described.
Quantitative Auger electron spectroscopy: Via the energy spectrum or the differential?
Authors: Seah M. P.
Published: December 2004

As part of an extended study of the quantitative analysis of surfaces by electron spectroscopy at the National Physical Laboratory, the quantification potential of Auger electron spectroscopy is examined in relation to the two modes of recording the spectra: the direct energy spectrum and the more customary differential energy spectrum. It is shown that it is not possible to describe a physically based routine procedure to obtain peak areas from the energy spectrum for Auger electron spectroscopy to be used, in the usual way, with a depth of analysis characterized by present values of the inelastic mean free path. These inelastic mean free paths are appropriate to measurements in the differential mode. The depth of analysis involved in peak areas form the energy spectrum may often be many times greater than these inelastic mean free paths, and may be rather indeterminate and matrix sensitive. In comparison, quantification in the differential mode is properly characterized in its depth of analysis. Quantification in this mode is most accurate in the usual framework of relative sensitivity factors, matrix factors, etc., by measurements at not too high a resolution (5 eV peak‐to‐peak modulation). The effects of peak shape changes, associated with changes in the energy loss structure with matrix, are removed by using the excursion of the negative peak as a measure of intensity instead of the usual peak‐to‐peak value. Other weak peak shape change are absorbed by the 5 eV modulation, whereas strong changes must be allowed for by relative sensitivity factors, etc., appropriate to the new peak shape.
Surface effect on the valence band Auger spectra of metals
Authors: Bose Shyamalendu M. , Foo E‐Ni
Published: December 2004

The shifts of the high energy peaks of the KVV Auger line shape of Li(100) and the L2,3 VV Auger line shape of Al(100) due to surface localization in the presence of a finite work function for the conduction electrons have been calculated. The results are sensitively dependent on the relative values of the distance of the surface afrom the first layer of ions and the mean free path λ of the ejected Auger electrons.
Investigation of the initial stages of oxidation of differently prepared aluminium by SIMS
Authors: Marton D. , Josepovits V. K. , Csanády Á.
Published: December 2004

The initial stages of oxidation of thin evaporated by SIMS. The highest ratio between the AIO+ ion yield at oxygen coverage ∂=0.13 and zero exposure was observed in the case of the thin film sample; moreover, for the diamond‐polished sample this ratio was higher than for the electropolished one. The Al+ ion yield was found to depend on the oxygen uptake and to show a linear function in the range of the oxygen does applied. Calculations were carried out in connection with the sputtering yields of the three differently prepared samples using the ion yield values obtained. The difference between the samples analysed is ascribed to the different oxide content of their surface layers.
Synchrotrons as sources for low energy Auger spectroscopy
Authors: Matthew J. A. D. , El Gomati M. M.
Published: December 2004

Unmonochromatized synchrotron sources are shown to be useful alternatives to electron beams in exciting low energy Auger transitions, and are likely to have applications where small concentrations of impurities in the surface of large samples are being investigated.
A SIMS and AES examination of a Cu/Co/Si alloy
Authors: Pavlyak Ferenc , Perczel I. Vajasdy , Giber János
Published: December 2004

The present paper deals with SIMS and AES examination of the layer structure developing during the annealing of a Cu/Co/Si alloy. It was discovered from the spectra and Auger images that there is a significant local increase of the concentration of the alloying materials. A surface layer develops during heat treatment of the alloy sample. We prove the presence of CoSi clusters and the joint enrichment of Si and Co.
Critical assessment by analytical electron microscopy of the significance of XPS measurements of the dispersion of supported catalysts
Authors: Delannay F. , Houalla M. , Pirotte D. , Delmon B.
Published: December 2004

The use of XPS intensity measurements to monitor the dispersion of supported catalysts becomes questionable in the case of an inhomogeneous repartition of the active species. Analytical electron microscopy permits the measurement of such inhomogeneitis. Two particular examples illustrate how misleading interpretations can be avoided by the combined use of these two techniques.
Potassium on the fracture surface of tungsten wires studied by AES
Authors: Menyhárd M.
Published: December 2004

Industrial tungsten wires were fractured using Auger equipment. The concentration of potassium on the fracture surface of the variously heat‐treated wires was markedly different. The results can be explained assuming that the wires were fractured along the potassium second phases. The spectra, similar to those normally interpreted as indicative of monolayer potassium segregation on the fracture surfaces, are here interpreted as arising from diffusion across the surface after fracture from the potassium inclusions and not from a segregated layer.
Thermal oxidation of GaOx Ny‐covered GaAs surfaces
Authors: Shiota I. , Nishizawa J.
Published: December 2004

The thermal oxidation of GaO x N y‐ covered GaAs surfaces is investigated mainly by means of a combined Auger‐sputtering method. It is shown that an oxide layer is formed mainly at the interface between the GaO x N y film and the GaAs on thermal oxidation in O2 gas, but the formation of the interfacial oxide layer is successfully suppressed by oxidizing in an atmosphere of O2 gas diluted with an excess amount of NH3 gas. The effects of oxidation temperature and the oxygen content in the GaO x N y film are further discussed. The properties of the interfacial oxide layer are compared with those of the oxide formed on free GaAs surfaces. Corresponding electrical properties are also examined.
Composition–Depth profiling and interface analysis of surface coatings using ball cratering and the scanning auger microprobe
Authors: Walls J. M. , Hall D. D. , Sykes D. E.
Published: December 2004

The provision of accurate composition–depth profiles to depths > 1 μm is important in the characterization and investigation of thick films, surface coatings, surface treatments and many other technologically important applications. At present, such profiles are usually achieved by sequential ion bombardment and surface analysis and hence involve many difficulties in interpretation due to the non‐uniform erosion of surfaces under ion bombardment. In this paper a method of obtaining accurate depth profiles is described using a ball‐cratering device. The method employs a rotating ball to fashion a well‐defined spherical crater in the sample surface, the depth and width of which can be accurately controlled. The specimen is then cleaned in situ using a scanning ion beam for a short period and the composition–depth profile is obtained either by point‐by‐point analysis down the sloping sides of the crater wall or by using Auger line‐scan techniques across the crater. Coating–substrate interface analysis can also be obtained by sputter–depth profiling at a point on the coating close to the exposed substrate. The method is not only considerably faster than ion etching, but the resulting depth profile also has a well‐defined depth resolution. Composition–depth profiles through nitrocarburized mild steel surfaces and protective surface coatings are presented to illustrate the usefulness of the technique.
The composition of Cu/Al thin films deposited by isothermal evaporation
Authors: Janda M. , Stefan O. , Kubový A. , Šťulík D.
Published: December 2004

The preparation and characterization of thin Cu/Al films is described. The single source evaporation process is treated theoretically and the calculated composition profile for a film prepared by evaporation of 5 wt% Al alloy is compared with the experimental data.
Problems of quantitative secondary ion microanalysis (SIMA) of low alloy steels
Authors: Illgen L. , Mai H. , Seidenkranz U. , Voigtmann R.
Published: December 2004

The applicablity of the National Bureau of Standards steel standards 461–468 and 662–664 for testing the CARISMA

Correction program for quantitative secondary ion analyses, supplied by ARL, Sunland, California, USA.

program has been investigated. Measurement of the secondary ion intensity of a number of alloying elements using 16O primary ions of 20 keV kinetic energy and a primary ion beam 130 µm in diameter gave results of good reproducibility for repeated samplings of the same specimen (Srel always <0.2), thus indicating a tolerable sampling error. But for some of the elements measured a bad correlation between the secondary ion intensity and the elemental concentration of different standard samples has been found. Carbon (an element of great importance for the properties of steels and of major influence on the outcome of CARISMA calculations) showed the most arbitrary behaviour in this sense. Detailed investigations of the microstructure and microcomposition of the standard samples by metallography, texture analysis, EPMA with X‐rays and backscattered electrons, and particularly by SIMA, showed that (a) the carbon secondary ion intensity is correlated to the sum of the Ti, Zr, Nb and Ta concentrations in the samples, and (b) the microvolumes of enhanced carbon secondary ion emission are mainly mixed carbides or carbonitrides of Ti, Zr, Nb and Ta.
Electron beam effects during analysis of glass thin films with auger electron spectroscopy
Authors: Ohuchi F. , Ogino M. , Holloway P. H. , Pantano C. G.
Published: December 2004

Migration of sodium in thin films of soda‐silica glass deposited on a stainless steel substrate has been studied. The amounts of charge trapping and local heating were a strong function of beam parameters for thin films. For example, the time required for the sodium Auger signal to decay to 50% of its initial value increased as the beam energy was increased or as the current density was decreased. The rearrangement of sodium due to charge trapping was calculated and compared to experimental data. The calculated and experimental data agree well and indicate that fields of ∼105 V cm−1 exist during analysis. The depth distribution of sodium indicates that either electrons or ion bombardment can cause sodium migration during analysis. The cross‐section for electron‐induced desorption was measured to be 3 × 10−20 cm2 for sodium in this glass, therefore it is only important at very high current densities.
Composition profile across a NiO/Ni interface determined from Auger electron peak shape analysis
Authors: Röll Klaus , Pamler Werner
Published: December 2004

The composition depth profiles of NiO layers grown on Ni metal were determined by AES and ion beam etching. As the shape of the Ni peak varies significantly with composition, a simple peak‐to‐peak (p‐p) analysis seems not to be applicable. Therefore the complete peak shape at any point of the profile was fitted by a superposition of a metal and an oxide peak. From the fit, the NiO content in the Ni matrix can be determined. Thus a quantitative analysis can be provided from the peak shapes. In addition to the more rigorous treatment, formulae for the p‐p amplitude have been developed which allow for the superposition of Ni and NiO peaks. Then an analysis can also be obtained with reasonable accuracy using the p‐p amplitudes only. The methods can be applied in materials where the peak shape changes due to a superposition of peaks.
Probing the influence of thin overlayers on the results of quantitative XPS analysis without reference samples
Authors: Ebel Maria F.
Published: December 2004

In contrast to physical methods with large information depths, the results of quantitative XPS analysis are strongly influenced by oxide and/or contamination overlayers with a thickness of 1‐2 monolayers. A new method is introduced which allows the determination of a value d/(Λref cos ε)without the application of the variable take‐off angle technique. The significance of the results and their associated errors are discussed.
Elastic peak electron spectroscopy for auger electron spectroscopy and electron energy loss spectroscopy
Authors: Gergely G.
Published: December 2004

Elastic peak electron spectroscopy deals with the spectra of secondary electrons in the neighbourhood of Ep primary energy and determines them in absolute units based on the Ne percentage of elastically reflected electrons. A procedure is described for evaluating elastic peak spectra. Experimental results on graphite, Si, Ge, stainless steel, Mo, W and Au polycrystalline samples are presented in the medium energy (Ep = 1–3 ke V) range. Spectra were measured with a cylindrical mirror analyser operated in the direct current mode. For elements (Si, Mo, etc.) Ne is determined mainly by the atomic number Z, Ne(Z)∼(Z – 26)0.65 was found for Z ≥ 26 and Ep = 3.1 ke V. The Ep dependence of Ne can be approximated by a power law Ne(Ep)∼Ep−β(Z), with β(Z) varying between 2 and 0.4 for the Z = 4–79 atomic number range. The elastic peak is composed of electrons escaping from a surface layer determined by the inelastic mean free path of primary electrons. Using Seah's values and from the Ne experimental data the backscattering cross‐sections were determined. They varied between 5 × 10−20(C)−2.8 × 10−18 cm2 (W, Au). Some new results are presented on the volume plasmon losses. In Si and Ge the mean free path of medium energy electrons is determined by the first volume plasmon loss, whereas in metals the contributions of other loss processes are important. It is practical to use the elastic peak and Ne as references for Auger and loss peaks allowing the estimation of ionization cross‐sections in Auger electron spectroscopy.
Rutherford back scattering and auger electron spectroscopy analysis of the oxygen distribution in the Al—Ag system evaporated at 10−4 Torr
Authors: Oliver Alicia , Santibáñez Federico Garcia
Published: December 2004

An analysis of the Al‐Ag system on thin films carried out through Rutherford back scattering and Auger electron spectroscopy combined with ion sputtering is reported. The films were prepared by evaporation on vitreous carbon under vacuum pressures of 1 × 10−4 Torr. The results show different distributions of oxygen depending upon the order of A1 evaporation.
Interface analysis of high insulating garnet materials using secondary ion mass spectrometry
Authors: Tolle H. J.
Published: December 2004

In this study, secondary ion mass spectrometry (SIMS) has been used to investigate the interface inhomogeneities of several μm thick layers of magnetic garnets grown on non‐magnetic garnet substrates. The epitaxial layers have the general composition Y3−x−zLaxPbzFe5−y Gay O12, whereas the substrate consists of Gd3Ga5O12. Bombardment of an insulator causes the sample to become charged, leading to loss of the secondary ion signal. This charge has to be compensated for by a simultaneous bombardment of the sample surface with electrons. The dependence of the Pb content (208Pb+) at the film‐substrate interface has been investigated as a function of the dipping parameters and the lattice mismatch. Layers are grown onto films with identical melt compositions but with different supercoolings. In all cases an enhanced Pb concentration at the beginning of the film growth process was found. With a specially grown inhomogeneous sample we were able to show the direct substitution of Pb and Y. The investigation of Ga within the transient layer is particularly difficult because of the high amount of this element in the substrate. The calibration of the count rate scale into formula units has been achieved by electron probe microanalysis (EPMA).
The application of inelastic electron tunnelling spectroscopy (IETS) to the study of surfactant adsorption upon an aluminium oxide surface
Authors: Langley A. J. , Oxley D. P. , Smith E. G.
Published: December 2004

Inelastic electron tunnelling spectroscopy has been applied to the study of sodium dodecanoate (laurate) adsorption, from aqueous solution, upon an aluminium oxide surface. AlAl2O3Pb tunnel junctions, whose oxides have been exposed to aqueous solutions of sodium dodecanoate are found to exhibit a maximum in resistance with increasing solution concentration. Spectral quality is dependent upon solution concentration, and optimum spectra are only obtained when junction resistance is near this maximum. The resistance maximum and decline in spectral quality with increasing solution concentration, are explained in terms of surfactant aggregation at a critical concentration. An optimum IET spectrum of sodium dodecanoate is presented and compared with the bulk infra‐red and Raman spectra of aluminium dodecanoate. A chemisorption mechanism is proposed. Other surfactants have also been investigated. These were sodium octadecanoate (stearate), sodium dodecyl sulphate and sodium hexadecyl sulphate. Problems specific to the application of inelastic electron tunnelling spectroscopy to these surfactants are reported.
Optical in situ sputter rate measurements during ion sputtering
Authors: Kempf J.
Published: December 2004

A laser optical technique is applied to secondary ion mass spectrometry/Auger electron spectroscopy for in situ sputter rate measurements. Phases and reflectances as measured during sputtering of opaque and transparent material give reliable results yielding the sputter rate interface position and interface region width. For opaque material there is a simple linear relation between the phase and the sputter rate. In the case of transparent material the sputter rate is determined from the phase or reflectance by using a more complex calculation.
Ion bombardment induced surface topography modification of clean and contaminated single crystal Cu and Si
Authors: Lewis G. W. , Kiriakides G. , Carter G. , Nobes M. J.
Published: December 2004

Among the several factors which lead to depth resolution deterioration during sputter profiling, surface morphological modification resulting from local differences of sputtering rate can be important. This paper reports the results of direct scanning, electron microscopic studies obtained quasi‐dynamically during increasing fluence ion bombardment of the evolution of etch pit structures on Si and Cu, and how such elaboration may be suppressed. It also reports on the elaboration of contaminant‐induced cone generation for different ion species bombardment. The influence of such etch pit and cone generation on achievable depth resolution is assessed.
Some aspects of a quantitative LEIS study of the potassium segregation at the V6O13(001) surface
Authors: De Gryse R. , Landuyt J. , Vandenbroucke L. , Vennik J.
Published: December 2004

The influence on the low energy ion scattering (LEIS) signal intensities of a potassium segregation is studied at 800 K. It is possible to alter the potassium surface concentration by means of electron stimulated desorption. The higher this concentration, the lower the absolute count rate of the complete LEIS spectrum. This observation suggests that, in the case of helium scattering at the V6O13(001) surface, Auger neutralization processes and/or adiabatic resonant transitions are active. This fact allows the calculation of an upper and a lower limit for the ratio of the scattering cross sections for oxygen and vanadium. From a comparison with theoretical predictions based on the Molière or Born—Mayer approximation of the Thomas—Fermi—Firsov potential, it follows that, under the given circumstances, low energy helium scattering is better described using the Molière approximation. By using this potential model, it is also found that at 800 K this potassium segregation is quite important giving rise to a steady state concentration of about one potassium atom per V6O13(001) surface unit cell.
Application of SIMS to heavy metal tellurides
Authors: Holland R. , Blackmore G. W.
Published: December 2004

A Cameca 3F imaging ion microanalyser has been used for the quantitative analysis of epitaxial layers of cadmium mercury telluride (CMT) and related materials on a variety of substrates. CMT has low thermal stability, readily losing Hg, and the erosion rate is unusually high. Nevertheless, satisfactory, reproducible, depth profiles are obtainable under constant erosion conditions. The positive secondary ion spectra of CMT, CdTe and HgTe are complicated by extensive interference by molecular ions and multicharged ions of the numerous isotopes of the matrix elements. The energy distributions of many of these are anomalous and the intensity varies non‐linearly with primary‐ion current density. It is shown that this anomalous behaviour is characteristic of the elements rather than the matrix. Wittmaack's theory of post‐sputtering ionization is confirmed by demonstrating that the intensity in these cases is proportional to the square of the primary‐ion current density and the effect is quantified for a variety of multicharged ions. Advantage has been taken of the low energy cut‐off of these species to overcome mass spectral interferences. Examples are given of the quantitative variation of trace elements through epitaxial layers as part of an on‐going analytical programme.
ESCA on Al films and on mechanically scraped surfaces
Authors: Wäsche M. , Linke E. , Richter K.
Published: December 2004

ESCA is used to characterize mechanically scraped Al samples and Al films. The results show that mechanical treatment is equivalent to other preparation techniques.
Correction factors and sputtering effects in quantitative auger electron spectroscopy
Authors: Holloway Paul H. , Hofmeister Susan K.
Published: December 2004

Quantification of Auger electron spectroscopy data from silver‐gold binary alloys has been studied. It is shown that the Auger data accurately reflect the bulk composition of scribed surfaces when the intensities of elemental standards are corrected for variations in the atomic density, electron escape depth and backscatter factor. It is also shown that gold is enriched in the surface region during sputtering with either argon or neon ions but the enrichment is less when sputtered at 110 K than at 300 K. Transients are observed in the concentration of gold and silver in the surface region when the ion energy is changed from 500 eV to 2000 eV. These sputtering effects (commonly called preferred sputtering) are interpreted as resulting from a combination of recoil implantation and surface segregation.
A simple background correction for AES peak height measurements
Authors: Labohm F.
Published: December 2004

A very simple background correction is described, which largely removes the error introduced by the AES background signal. The correction consists of adding a fixed amount, equal to the change in the background across the AES line, to the measured peak height. The correction is particularly important for the measurement of small coverages of elements displaying AES lines in the low energy range of the spectrum. No computer is necessary. An example concerning C on Ni(100) is given.
Core level binding energy shifts in dilute tin alloys
Authors: Hegde R. I.
Published: December 2004

X‐ray photoelectron spectra of Cu95Sn5 and In95Sn5 alloys have been recorded using a VG Scientific ESCA‐3, MK II electron spectrometer. The binding energy of Sn 3d level in these alloys is compared with that in pure Sn(ß). From the above results, and also from those published earlier, it is clear that the binding energy shift depends on the electronegativity difference, the coordination number and also the interatomic distance. A simple empirical equation was arrived at to get the best fit with the experimental data. In general the agreement between the calculated and measured binding energy shifts is quite satisfactory.
Preparation of self‐supporting anodic barrier films on aluminium for backscattering analysis
Authors: Shimizu K. , Skeldon P. , Thompson G. E. , Wood G. C.
Published: December 2004

A technique for the preparation of self‐supporting windows of anodic barrier films on aluminium, which are essential for the precise interpretation of Rutherford backscattering data, is described. The generation of the window comprises several steps which include: (1) electropolishing of the superpure aluminium specimen in a perchloric acid/ethanol mixture; (2) masking a region of surface of the electropolished specimen with ‘Lacomit’ paint; (3) anodizing to develop a barrier‐type anodic film over the exposed aluminium surface; (4) removal of the paint to reveal the non‐anodized region on one face of the aluminium specimen which is then removed by electropolishing to leave the film window. Following this procedure, self‐supporting windows of anodic films, free from the aluminium substrate, having effective diameters up to about 10 mm, are produced. It is shown that the use of the self‐supporting window enables the Rutherford backscattering technique to be used to its full potential for the analysis of the barrier‐type anodic films, enabling Al and O profiles through the film to be resolved clearly.
Element‐Specific broadening effects in SIMS depth profiling of light impurities implanted in silicon
Authors: Wach W. , Wittmaack K.
Published: December 2004

Beam‐induced broadening effects in SIMS depth profiling have been studied for eight impurities (Li through Al) implanted in amorphized silicon at energies between 1 and 15 keV. Depth profiling was performed under Ar+ (⩽2.5 keV) or O (⩽3 keV) impact. In selected cases (Li, N) the effect of the probe energy has also been investigated. The measured profiles show exponential tails. The decay length γ characterizing these tails exhibits strong oscillations when plotted as a function of the atomic number of the dopant. Maxima are seen for N and O (γ ≃ 7 nm) as well as for Mg (γ ≃ 13 nm), minima for B and Na (γ ≃ 2 nm). The results suggest that the observed effects are due to a yet unpredictable combination of collisional mixing, defect‐assisted diffusion and selective sputtering.
Imaging XPS—A new technique, I—principles
Authors: Gurker N. , Ebel M. F. , Ebel H.
Published: December 2004

XPS imaging promises to be a powerful analytic tool because it enables specific information on both elements and bonding to be recorded on a two‐dimensional distribution map. As far as the authors are aware, the only scanning XPS method to date which has been found to be practical is essentially a scanned‐particle‐beam method, like scanning AES, and it is only applicable to thin film specimens. This paper provides the basic ideas of a new imaging XPS technique based on a quite different concept. It will be applicable to any kind of specimen that can be analysed in a conventional XPS system. It makes use of the dispersion properties of a spherical condenser‐type spectrometer and applies a two‐dimensional electron detection device for decoding the energy and emission position of an analysed photoelectron. Experimental arrangement and theory of operation are presented.
In situ characterization of electrode–electrolyte interfaces using spectroscopic techniques
Authors: Miles R.
Published: December 2004

A review of ultraviolet/visible, infra‐red and Raman spectroscopic techniques (excluding ellipsometry), applied to the in situ characterization of immersed electrodes is presented. Literature reports involving transmission and internal reflectance at optically transparent electrodes, and also external specular reflectance at planer electrodes both in the visible and in the infra‐red spectral regions are described. Rman techniques covered include not only recent developments in surface‐enhanced Raman scattering but also unenhanced Raman scattering, resonance Raman scattering and other non‐linear processes. Specialized instrumentation requirements are discussed and experimental methodology relevant to the characterization of electrochemical systems is outlined. The report concludes by highlighting the advantages and limitations of the various in situ spectroscopic techniques indicating likely areas of development in the future.
Adsorption of NO on a Rh‐10% Pt (111) surface: Non‐uniform spatial distribution
Authors: Holloway P. H. , Williams F. L.
Published: December 2004

Most studies of chemisorption now use single crystals in order to distinguish the effects of crystallite orientation upon absorption and to have a ‘large, uniform’ surface for measurement. Also, many of the analytical techniques require surface areas 1 mm in diameter for measurements. Most investigators implicitly assume that a single crystal will provide a uniform surface over these dimensions. This is not always true as will be shown in this case for NO absorption on Rh‐10% Pt (111) crystals. Therefore, the purpose of this communication is to show that high spatial resolution surface analysis can be very useful in studying surface/gas reactions, even on single crystal surfaces.
Surface quantitative analysis of CrO systems by XPS
Authors: Battistoni C. , Cossu G. , Mattogno G. , Paparazzo E.
Published: December 2004

A comparison among O/Cr atomic ratios obtained from XPS Cr 2p3/2 and O 1s spectra in pure inorganic compounds, employing the Elemental Sensitivity Factors approach and the so‐called ‘First‐Principles Model’ is reported.
Use of a fast atom beam in ion microscopy (FABIM) for analysis of poorly conducting materials
Authors: Degrève F. , Lang J. M.
Published: December 2004

A Cameca IMS3f ion microscope was modified to allow the analysis of poorly conducting materials. A neutralization chamber within the primary ion column constitutes a fast atom beam (FAB) source. The insertion of a thin metallic diaphragm between the sample and the sample holder minimizes the charge build‐up. With these simple and cheap modifications, it is possible to change instantaneously from ion to neutral beam excitation for the same analysed area. The characteristics of the primary neutral beam were evaluated and the analytical possibilities using positive and negative secondary ions were investigated on various poorly conducting materials (mineral, multilayered glass, organic). The unique advantages of combining FAB and Ion Microscopy (FABIM) are illustrated: imaging capability, low detection limit, mass spectra at low and high resolution and depth profiles on very small areas. Suggestions are proposed to improve the performance of this preliminary FABIM design.
Oxidation of Ni3Al at low and high oxygen pressures
Authors: Venezia A. M. , Loxton C. M.
Published: December 2004

Oxidation of stoichiometric Ni3Al performed at elevated temperatures in low oxygen partial pressure and in atmospheric oxygen has been studied by x‐ray photoelectron spectroscopy, auger electron spectroscopy and x‐ray diffraction. At low oxidation pressure only the aluminum oxide is found although there is evidence for a phase change at temperatures above 600°C. At atmospheric pressure, NiO, NiAl2O4 and Al2O3 are obtained. The different behavior is discussed in terms of the relative standard free energy of formation of the oxides.
Nitrogen 1s charge referencing for Si3N4 and related compounds
Authors: Donley M. S. , Baer D. R. , Stoebe T. G.
Published: December 2004

This paper describes the method used to produce a Si3N4 standard for use as a reference material in XPS measurements of silicon nitride related compounds. The reference material was made by high dose ion implantation of N+ into a (100) Si wafer and annealing the wafer at 1150°C. Rutherford back‐scattering measurements and an Auger depth profile confirmed that after the anneal a subregion of Si3N4 was formed. X‐ray photoelectron spectroscopy (XPS) spectra were collected for Si 2p, N 1s and Si KLL lines. Signals from both elemental Si and Si3N4 were observed, with no indication of specimen charging. The N 1s binding energy was determined to be 398.5 eV. Modified Auger parameter plots of the data showed results consistent with other careful measurements for Si and Si3N4. Because data from several studies indicate that the N 1s peak is relatively insensitive to minor compositional changes, the N 1s line can be used as a charge reference for the analysis of Si3N4‐based materials. This charge reference can reduce the uncertainty in binding energy measurements on these generally insulating materials to ±0.1 eV.