bluuebunny/crossref_metadata_2025 huggingface dataset:
Stereological analysis of dislocation arrangements in crystals from TEM images
Authors: Hanisch K.‐H. , Klimanek P. , Stoyan D.
Published: January 2007

Ideas of stochastic geometry have been used in order to develop procedures for stereological characterization of dislocation arrangements in crystals from TEM images. Two conceptions, which can be taken for promising in much cases, are presented in some detail: analysis of statistically homogeneous defect distributions by means of pair — correlation functions and interpretation of statistically inhomogeneous dislocation arrangements in terms of a so‐called Voronoi‐mosaic. Practical application of both methods is demonstrated by analysis of dislocation configurations occurring in metallurgy and solid‐state technology.
Superlattices and composition of phases of CVD layers based on TiCx, VCx, (Ti, V)Cx, and (Cr, Fe)7C3
Authors: Paulat E. , Lenk P.
Published: January 2007

Protective layers of TiCx, VCx, (Ti, V)Cx, and (Cr, Fe)7C3 on C100W1 tool steel have been investigated by X‐Ray and electron diffraction. Superlattices have been observed in the VCx− and (Cr, Fe)7C3−layers. As manufacturing of (Ti, V)Cx−layers the growth of carbides with low content of V and Ti respectively has been prefered.
The importance of the oxygen ion concentration for oxidic high‐temperature solvents
Authors: Sinn E. , Linzen D. , Fischer K.
Published: January 2007

Using e.m.f. measurements we determined relative oxygen ion concentrations of the systems PbO—PbF2—B2O3, PbO—MoO3—B2O3, PbO—Bi2O3—V2O5, 3 PbO · MoO3—Fe2O3, and 3 PbO · MoO3—Ga2O3. Furthermore the alteration of the relative oxygen ion concentration of pure PbO was observed after stepwise addition of the solvent components PbF2, B2O3 and of the garnet forming oxides Fe2O3 and Y2O3 giving complete high temperature solutions for the Y3Fe5O12 preparation. Applying the Lux' acid‐base concept the behaviour of these oxide mixtures is discussed. Combinations which contain weak bases and weak acids allow the adjustment of a desired oxygen ion concentration that is little changed by added oxides for crystal growth. These combinations show favourable properties as solvents for oxidic substances with complicated compositions, e.g. perovskites, garnets, ferrites.
Some new electrically conducting complexes of nickel chelates
Authors: Oza A. T.
Published: January 2007

Some new complexes of organo‐metallic nickel chelates with organic donors and acceptors and with halogens are found to have electrical resistivities lying in the semiconducting range. The results are discussed here briefly in terms of intermolecular interactions and molecular packing in the solid state. Ni3O2(OH)4 — a mixed valence nickel compound was found to have metallic conductivity in the form of single crystals.
Crystallization of hydrocarbon (n‐C28H58): Fatty acid (CH3(CH2)14COOH) mixtures
Authors: Prasad P. B. V.
Published: January 2007

Crystallization of hydrocarbon (n‐octacosane), fatty acid (palmitic acid) and mixtures of hydrocarbon: fatty acid (n‐octacosane:palmitic acid) is carried out by the solvent evaporation method. The ability of palmitic acid to crystallize is compared with that of the hydrocarbon. Observations on the growth of palmitic acid as ring spherulites on the hydrocarbon crystal substrates is presented. Occurrence of alternatively bright and dark zig‐zag lines in some of the spherulites is attributed to a repeated twisting of the fibrous crystals of palmitic acid.
The silicon impurity as a possible growth‐regime indicator for LiNbO3 crystals
Authors: Erdei S. , Szaller Zs. , Raksányi K. , Matók Gy.
Published: January 2007

The influence of Si concentration and temperature regimes on the visually observable properties of LiNbO3 single crystals grown by Czochralski method was studied. Si concentration measurements were carried out and minima in the radial and axial distribution curves have been established. An upper estimate is given for the equilibrium distribution coefficient of Si in LiNbO3. A direct correlation has been found between the degree of opacity and the Si concentration. The variation of the Grashof number during growth and a correlated modification of the structure of the concentration layer width, implying a position dependent fulfilment of the Hurle‐Bardsley criterium for constitutional supercooling, accounts reasonably well with the visually observable properties of the opaque regions appearing in the course of crystal growth. The use of Si as an overall indicator for the characterization of growth regimes is discussed.
Structure of monoclinic acridine orange hydrochloride monohydrate, C17H19N3· HCl · H2O
Authors: Kuban R.‐J. , Kulpe S. , Schulz B.
Published: January 2007

Mr= 319.82, monoclinic P21/a,Z= 4,a= 14.545(5),b= 15.562(6),c= 8.538(4) Å, β = 120.66(3)°,V= 1662(1) Å3,Dm= 1.27 Mgm−3,Dx= 1.278 Mgm−3, λ(MoKα) = 0.71069 Å, μ(MoKα) = 0.24 mm−1,T= 297 K. FinalR= 0.049 for 1485 observed reflections. All hydrogen atoms were located and refined isotropically. Bond lengths (σ = 0.004 Å) and angles (σ = 0.3°) are normal. The substance is a derivative of acridine. The structure consists of chloride anions, bisdimethylaminoacridinium cations and water molecules. In the solid state the molecules are approximately planar. Pairs of cations form dimers with parallel planes connected by an I inversion centre and plane distances of 3.474 Å. They overlap with partial areas of all three six membered rings.
Effect of low temperature thermocycling on microhardness anisotropy of commercially pure beryllium
Authors: Lavrentev F. F. , Pokhil Yu. A. , Shayaeva Ch. Yu.
Published: January 2007

Commerically pure beryllium polycrystals prepared by hot uniaxial crucible extrusion have been used for statistical investigation of the microhardness distribution on various faces distinguished by the orientation with respect to the extrusion axis. The microhardness anisotropy coefficient K (the relative difference of the statistical average values of microhardness for faces perpendicular and parallel to the extrusion axis) of the tested material was high. Low temperature thermocycling between 300 and 77 K essentially reduced K, which is thought to be a result of structural state changes and internal stress redistribution in the material induced by thermoeleastic stresses due to thermocycling.

The result of the experiment is in qualitative agreement with data on the beryllium defect structure and fracture character found by transmission and scanning electron microscopy.
Determination of carbon, silicon and boron content in semi‐insulating GaAs by infrared absorption spectroscopy
Authors: Ulrici B.
Published: January 2007

Measurements of the local vibrational mode (LVM) absorption of 12CAs at 582 cm−1, 28SiGa at 384 cm−1 and (10)11BGa at (540 cm−1) 517 cm−1 can be used to determine the concentration of these residual impurities in semi‐insulating (SI) GaAs. Although the energy‐limited resolution of a grating spectrometer does not allow measuring the line shape of the narrow LVM bands in GaAs the intensity of it determined with definite spectral slit width (SSW) is a reliable measure for the respective impurity content. Calibration factors given in the literature and peculiarities in the measurements and evaluations for the different impurities are discussed.
A fluctuation theory of normal crystal growth in the case of one‐component metallic macrosystems
Authors: Chistyakov Yu. D. , Baikov Yu. A.
Published: January 2007

A Model of spontaneous fluctuations of the limited spectrum solid state particle concentrations in the case of one‐component metallic macrosystems is considered. Within the small supercoolings' region of the melt‐crystal macrosystem a normal law of crystallization is established due to the action of fluctuation mechanism. For some metallic macrosystems a comparison on the crystallization kinetics between the theory and experiments has been realized. Some quantitative restrictions of the melt‐crystal system supercoolings' region within which the mechanism of spontaneous fluctuations is expected to be realized are established for a collection of one component metallic macrosystems. Two‐phase transitional zone length's influence on the values of admitted supercoolings in presented.
Partition coefficients of rubidium and cesium in the process of crystallization of the sodium chloride melt
Authors: Smirnova E. P. , Kravchuk I. F. , Tikhomirova E. I.
Published: January 2007

Partition coefficients of rubidium and cesium between the crystal and melt of the sodium chloride have been determined by the directed horizontal crystallization and Czochralski methods. Rudidium and cesium partition coefficients were found to be constant in the studied concentration range < 1%, and insensitive to the presence of third microimpurity in the system. The theoretically calculated partition coefficients agree well with the experimentally measured coefficients.
Statistic analysis of partition coefficients for crystallization cleaning methods
Authors: Nisel'son L. A. , Yaroshevsky A. G.
Published: January 2007

Statistic estimation of experimental determination reliability for the distribution coefficient, K, (crystal‐melt equilibrium) has been made on the basis of independent measurement comparison. Reliability of these data is shown to be low. Frequency K histograms have been constructed both for simple element set and halogenides. Histogram maximum shift to lg K < 0 has been obtained.
X‐ray powder diffraction and 1H‐NMR studies of phase transitions in tetra‐n‐butylammonium octacyanotungstate (V)
Authors: Czerwonka J. , Hodorowicz S. A. , Samotus A. , Kanas A. , Sagnowski S. , Rydzy M.
Published: January 2007

[(n—Bu)4N]3 W(CN)8 is investigated by X‐ray powder and wide‐line proton magnetic resonance methods. The temperature dependences of the lattice parameters and 1H second moment of the resonance lines are recorded in the range of 77 to 383 K. On ground of the dynamical model proposed for the crystal lattice of the compound an analysis of the experimental data is made. The reorientations of different groups of the cations are proved to be responsible for the observed effects.
Interfacial stability and grain diameter of the metal phase of directionally solidified Al‐Si‐type eutectics
Authors: Vetter Jörg , Schmidt Günther , Frühauf Joachim
Published: January 2007

The morphology of the solid‐liquid interface and the metal phase grain diameter of Al—Si‐type eutectics (Al—Si, Ag—Si, Ag—Ge, Zn—Ge) were investigated in the range of a growth rate R = 0.2 … 20 mm/h and of a temperature gradient at the solid‐liquid interface G = 2 … 25 K/mm. Three types of interfacial morphologies depending on the G/R ratios were found out. The G/R ratio of the transition from a planar to a nonplanar solid‐liquid interface corresponds to the critical G/R|c ratio, which can be calculated by the criterion of the constitutional undercooling. The grain diameter of the metal phase depends on growth parameters as follows: dK ∼ R—rG—g with r = 0.33 … 0.43 and g = −0.37 … 0.03.
Chemical and LP‐etching of gallium antimonide substrates
Authors: Pramatarova L. D. , Baeva M. B. , Yordanova I. M.
Published: January 2007

This paper presents the results of the chemical and Liquid Phae (LP) Etching of the GaSb substrates. The method of anomalous transmission for X‐ray topographic imaging of dislocations was used. It is shown that the dislocation density lowers with decreasing of the Sb content in the Ga melt at the LP‐etching.
Induced smectic A phase by homeotropic orientation in 4, n‐octyloxybenzoic acid (OOBA) at nematic‐smectic C phase transition
Authors: Simova P. , Petrov M.
Published: January 2007

Using homeotropic and quasi‐homeotropic orientation in thin film of 4‐n‐octyloxybenzoic acid, we indicated intermediate smectic A‐like state during the nematic‐smectic C phase transition. Pseudoisotropic and focal conic textures are characteristic for homeotropic and quasihomeotropic orientations respectively. The smectic A‐like state induced by the boundary conditions exists in a very short (about 0.5 °C) temperature region.
Heat and mass transfer problems in solution growth of GaP crystals by the travelling solvent method (TSM)
Authors: Nghi Nguyen Thanh
Published: January 2007

The influence of the natural convection on the heat and mass transfer process during growth of GaP crystals from the solution is considered. The two‐dimensional quasi‐stationary thermodiffusive hydrodynamic problem for the GaP growth system by travelling solvent method (TSM), as a model, has been solved. Computation is given for the temperature and concentration field distribution in the solution. The picture of vortex configuration for different lengths of the liquid zone, the shape of the growing and dissolving interfaces and also the boundary layers thickness are obtained. The experimental dependence of the growth rate on the convection intensity observed mostly confirmed the calculation results.
Crystallization of hydrocarbon (n‐C28H58): Fatty acid (CH3(CH2)14cooh) mixtures (II). The thermal effect
Authors: Prasad P. B. V.
Published: January 2007

Studies on the crystallization of mixtures of palmitic acid: n‐octacosane at elevated temperatures is presented. The crystallization temperature is seen to have a pronounced effect on the morphology of the banded structures. The fibre twist which is responsible for the band formation, is interpreted as due to a thermal stress. Crystallization of some other compounds in the presence of n‐octacosane is described and the results are discussed.
Microscopic investigations of morphological structures on the pyramidal faces of KDP and DKDP single crystals
Authors: Hilscher H.
Published: January 2007

Studying a number of {101} faces of KDP and DKDP single crystals in the as‐grown state we found in most cases one, rarely few, clearly stepped growth hillocks covering the whole face. The geometry of these growth hillocks was determined from photomicrographs; the step heights were measured with a profilometer. To prove our results we carried out X‐ray topographic investigations and in‐situ observations on KDP crystals. In addition we studied the as‐grown faces of ADP and LiJO3 single crystals.
A new method for determining the thickness and composition of thin layers by electron probe microanalysis
Authors: Hunger H.‐J. , Baumann W. , Schulze S.
Published: January 2007

A new method is described which allows the determination of thickness and composition of thin layers by EPMA simultaneously. The method is based on new depth distribution functions of the characteristic X‐rays and on a substrate correction which was developed by the authors. The test of this method with the aid of wellknown layers gives very good results. The method works with massive standards. Layers for calibration are not needed.
On the quench‐sensitivity of AlZn alloys during RT‐ageing in dependence on alloy composition
Authors: Hübner G. , Löffler H.
Published: January 2007

The quench‐sensitivity (variation of Tq) of the decomposition rate at RT was studied for four AlZn(X) alloys (X = 3.0; 4.5; 8.0, and 12.0 at. %) by SAXS. It was found that the occurring “inversion temperature” depends on alloy composition and, particularly for the two alloys with the highest zinc content, on ageing time.
The local distribution of luminescence generation in LED's
Authors: Oelgart G. , Stegmann R. , Kaatsch D.
Published: January 2007

Mit Hilfe der Temperaturabhängigkeit der Katodo‐ und Injektionslumineszenzintensität wird die lokale Verteilung der Lichtgeneration in lichtemittierenden GaAs1−xPx‐Dioden als Funktion des Flußstromes und der Herstellungstechnologie untersucht. Für geringes Injektionsniveau rekombinieren die Überschußladungsträger in einer hochkompensierten Schicht während mit steigendem Flußstrom das Licht im Volumen des n‐ und p‐Gebietes generiert wird. Das Injektionsverhältnis wird durch die Herstellungstechnologie des p‐n Überganges bestimmt.
Investigation for ferroelectric domains by scanning electron microscopy
Authors: Röder A. , Scheiding C.
Published: January 2007

Examples for the direct observation of domain structures in ferroelectric crystals by means of scanning electron microscopy are given. The results for TGS and AFB crystals with direction of the polarization vector perpendicular to the observed surface are presented with respect to temperature changes, to domain enlargement under the influence of an external electric field and to the influence of X‐ray‐ and γ‐radiation on the domain formation.
Thermotropic liquid crystalline compounds with lateral long‐chain substituents (IV). Physical properties of 1,4‐bis‐[4‐n‐octyloxybenzoyloxy]‐2‐n‐alkylbenzenes
Authors: Demus D. , Diele S. , Hauser A. , Latif I. , Selbmann Ch. , Weissflog W.
Published: January 2007

In 15 Substances of general formula magnified image transition temperatures, transition enthalpies and entropies, densities and phase transition volumina, order parameters of a dissolved dye and optical refractive indices were measured. Additional miscibility and X‐ray investigations were performed. The results are discussed on the basis of molecular statistical theories of the nematic state and point to a conformation of the long lateral chains which is nearly parallel to the molecular long axes. The results further show the dominating importance of the steric repulsive forces in stabilizing the nematic state.
Studies on epitaxial growth of organic compounds on sucrose by the fourier transform method (I). On crystal growth of the participants
Authors: Adler H.‐J. , Follner H.
Published: January 2007

Epitaxial growth of organic compounds on sucrose crystals has been observed. In any case two‐dimensional lattice analogies exist. The structural relations are, as a rule, unknown. In the present first part crystal growth of the participants was investigated. Equilibrium and growth forms of host (sucrose) and guest crystals (β‐succinic acid, hexachlorobenzene, anthraquinone, isatin) have been determined by the Fourier transform method. The growth polyhedra fully correspond to the experimental observations.
RHEED Measurements of AgGaSe2 thin films flash evaporated onto {111} a‐GaAs
Authors: Tempel A. , Schumann B. , Kühn G.
Published: January 2007

AgGaSe2 thin films were prepared by flash evaporation on {111} A‐oriented GaAs substrates and investigated by reflection high energy electron diffraction (RHEED). Epitaxial growth takes place in the substrate temperature interval of Ts = 845–920 K. The azimuthal orientation of the deposit on the substrate is discussed, supposing a AgGaSe2 c/a ratio of 1.82. It is shown that detection of twin formation in the films is possible from RHEED measurements in the <211>‐azimuths with respect to the substrate.
Microstructure and spacings of directionally solidified metal‐semiconductor eutectic alloys
Authors: Vetter J. , Frühauf J. , Schmidt G.
Published: January 2007

Directionally solidified metal‐semiconductor eutectic alloys, representing nonfacetted facetted eutectics, show a variety of microstructures caused by the great differences in semiconductor volume fraction (ZnGe 7,8 %; GeZrGe2 98.6 %), the influence of growth rate and temperature gradient at the solid‐liquid interface. The AlSi, AgSi, AgGe, ZnGe, Cu3SiSi, NiGeGe, CoGe2Ge, Mn3Ge2Ge, FeGe2Ge, Mn11Si19Si, Cu3GeGe, GeTiGe2 and GeZrGe2 eutectics habe been investigated. The following three models are applicable for the calculation of the spacings as a function of growth rate and temperature gradient at the solid‐liquid interface to certain microstructures: diffusion‐determined growth, branchinglimited growth and phase‐lead‐determined growth.
Electronic structure investigation of V1−xNbxO2 mixed oxide by XES and XPS
Authors: Werfel F. , Rohländer D.
Published: January 2007

The mixed oxide system V1−xNbxO2 (x ≦ 0.12) has been studied by X‐ray and photo‐emission spectroscopy as a function of the composition. The metal L valence band spectra (VLIII and NbLβ2.15) with increasing Nb concentration change their width and relative band intensity substantially pointing to charge flow and hybridization effects. The XPS valence band for x ≧ 0.04 indicates a total d band shift of 0.4 eV relative to smaller Nb concentrations. The measured core level spectra at higher Nb doping x ≈︁ 0.10 support the expected existence of V3+‐Nb5+ pairs. A comparison of different X‐ray spectra and the XPS valence band spectrum for x = 0.08 exhibits a more stronger V3d localization relative to Nb4d, favouring charge transfer and bonding variations with Nb doping. Our spectroscopial data confirm the established ideas concerning the electronic structure of rutile‐like compounds and its change at the phase transition point.
Vapour Phase Epitaxy of GaxIn1−xAs in the GaInHClAsH3H2‐System Using a Mixed Ga/In Source
Authors: Jacobs K. , Bugge F. , Simon I.
Published: January 2007

The mixed crystal composition of GaxIn1−xAs layers is analysed as a function of the composition of a mixed Ga/In source during VPE in the hydride system. Experimental results are compared with thermodynamic calculations. Both thermodynamics of the deposition reactions and thermodynamies of the souree reactions are considered in the calculations.
Main Factors Influencing the Crystal Size Distribution from a Batch Cooling Crystallizer
Authors: Chianese A. , Di Cave S. , Mmazzarotta B.
Published: January 2007

An experimental investigation was carried out with a view to characterizing the influence of some typical operating factors on the size distribution of the crystal product obtained from a batch cooling crystallization. Reference was made to K2SO4 crystallizing from aqueous solutions, a system for which some data are available in the literature making possible some interesting comparisons. The obtained results indicate that a consistent improvement of the product size distribution can be achieved by limiting the stirring rate, by the use fo seeding, and by the presence of a draft‐tube, in that order; little in‐fluence seems to have the cooling medium temperature. Quite important is also the cooling policy adopted and in this sense a linear cooling curve lead to the best product quality.
Techniques for Generation of Supersaturation Applicable to the Precipitation of Barium Chromate
Authors: De Silva R. L. , Creasy D. E.
Published: January 2007

Possible techniques for generating supersaturation, which could be applied to precipitation of barium chromate from aqueous solution, are reviewed, and experimental work carried out to examine the feasibility of the more promising of these techniques are described. The process requirements of a reasonable rate of production of relatively large (∼ 100 μm) crystals of normal habit, are shown to be satisfied by the technique of precipitation from homogeneous solution (PFHS), employing urea hydrolysis to cause a controlled change in the solubility of barium chromate in an acidic aqueous medium. Some recent experimental work on urea hydrolysis, as applied to the precipitation of barium chromate, has been reanalysed and found to be in agreement with the generally accepted, pseudo‐first order reaction model. The effects of urea hydrolysis on the precipitation process are discussed.
Structural Changes During Cutting of Mo Crystals
Authors: Larikov L. N. , Maximenko Ye. A.
Published: January 2007

Structural changes occurring in a shaving and in product during cutting of Mo single crystals as well as softening processes during annealing after cutting are investigated.

The extremal deformation are created when the shaving is removed and as a result the dynamic recovery process with lattice reorientation takes place.

The strong deformation heterogeneity, which is revealed as the two‐scale recrystallisation processes during isothermal annealings, and its localisation in separate sections of the specimens was observed.

During high‐temperature annealings of the product and shaving the matrix‐crystal orientation recovery occurs by means of absorption of the recrystallised layer by undistorted matrix.
Peak Position Determination of X‐Ray Diffraction Profiles in Precision Lattice Parameter Measurements According to the Bond‐Method with Help of the Polynomial Approximation
Authors: Grosswig S. , Jäckel K.‐H. , Kittner R.
Published: January 2007

The possibilities and limits of the polynomial approximation for an accurate determination of the peak position of X‐ray diffraction profiles in precision lattice parameter measurements according to the BOND‐method are investigated. The use of a polynomial approximation with reciprocal measuring values leads to an improvement of the convergence properties of the approximation and allows to use polynomials with lower degree. A practicable criterion of the choise of optimum approximation parameters is given. It is shown that the accuracy of the determination of the peak position which is needed for precision lattice parameter measurements with an accuracy of about Δd/d ≈︁ 10−7 is attainable under usual experimental conditions.
Unusual Thermal Behaviour of Mercurous Chloride
Authors: Venudhar Y. C. , Iyengar Leela , Rao K. V. Krishna
Published: January 2007

A precise determination of the lattice parameters and the coefficients of thermal expansion of mercurous chloride has been made at different temperatures ranging from 30 °C to 260 °C with a Unicam 19 cm high‐temperature powder camera and FeKα radiation. The ‘a’ parameter increases non‐linearly, whereas the ‘c’ parameter decreases linearly with temperature. Both the c/a value and the unit‐cell volume are found to decrease with increasing temperature. The coefficient of thermal expansion along the ‘c’ axis, α∥, is found to have a constant negative value throughout the range of temperature studied. The positive value of α⊥ increases while the negative value of volume coefficient (β) decreases linearly with increasing temperature indicating an unusual and interesting thermal behaviour.
X‐Ray Determination of the Mean Amplitude of Vibration and Debye Temperatures of KRS‐5 (TIBr0.46I0.54)
Authors: Srinivas K. , Sirdeshmukh D. B.
Published: January 2007

The X‐ray diffraction intensities of Bragg reflections have been measured for KRS‐5 (TIBr0.16I0.54) at room temperature. From the observed intensities the mean Debye‐Waller factor and the X‐ray Debye temperature have been evaluated. The values of the Debye‐Waller factor, mean square amplitude of vibration and the Debye temperature are 2.73 ± 0.06 Å2, 0.104 ± 0.002 Å2 and 90 ± 1 K, respectively.
The Precipitation of Alkaline‐Earth Metal Polyacrylate Hydrate Powders from Aqueous Solution: Ionic Equilibria, Precipitate Compositions and Morphologies
Authors: Packter A. , Sabir S.
Published: January 2007

The precipitation of barium, strontium, calcium and magnexium polyacryate hydrates was studied from equivalent aqueous solutions of initial concentrations 0.03 M to 0.30 M at ambient temperature: sodium polyacrylate (m. wt = 30,000 to 300,000) was added to metal chloride solution. The final yields of precipitate increased with decreasing solubility and/or peptisation (Ba > Sr > Ca > Mg) and increasing molecular weight of the polyacrylate; the precipitates had the compositions [BaA(COO)2 · 1–2H2O]n, [SrA(COO)2 · 1–2 H2O]n, [CaA(COO)2 · 2 H2O]n and [MgA(COO)2 · 2 H2O]n.

The final yields of the precipitates from sodium polyacrylate solutions were far lower and these had the compositions [Na2αM1‐αCA(COO)2 · 2 H2O]n; A = CHCH2CH.

The metal polyacrylate hydrate powders consisted of microcrystalline ‘spherules’; their average diameters were from 0.03–0.05 μm (for lower m. wt products) to 0.01 to 0.02 μ,m (for higher m. wt products).
Thermodynamic Calculation of the Alloy Composition of GaxIn1−xAs Grown in the Trichloride System Using Solid Sources
Authors: Simon I. , Jacobs K. , Butter E.
Published: January 2007

The dependence of the GaxIn1−xAs alloy composition as a function of the experimental input variables is calculated for a growth system using AsCl3 and solid GaAs and InAs sources. The results are similar to those earlier obtained for growth in the hydride system. Additional AsCl3 introduced downstream the source regions shifts the alloy composition towards higher GaAs content.
Luminescence and Photoconductivity Caused by Antisite Defects in CdIn2S4 Single Crystals
Authors: Georgobiani A. N. , Gruzintsev A. N. , Ratseev S. A. , Tezlevan V. E. , Tiginyanu I. M. , Ursaki V. V.
Published: January 2007

Results of a study of the influence of nonstoichiometry as well as of annealing and argon ion implantation on photoluminescence and photoconductivity spectra of cadmium thioindate single crystals are presented. The energy positions of levels of antisite Incd and CdIn defects are found. The role of antisite defects in the process of conductivity compensation is analysed.
The Role of Impurity Precipitation on Ionic Conductivity of NaCl:Sr System
Authors: Reddy K. Narasimha , Sayanna R.
Published: January 2007

Ionic conductivity studies of NaCl crystals doped with 1 mole% of strontium both in as grown state and after quenching them from 550°C indicate that the conductivity depends on the impuritiy precipitates. It is found that all conductivity plots of pure NaCl, NaCl:Sr and NaCl:Sr crystals quenched from 550°C are straights lines, both in extensive and intrensic regions. The conductivity of NaCl: Sr system is always less than that of pure NaCl crystal. The results are explained on the basis of state of dispersion of impurities.
Analysis of Stress Distribution in Semiconductor Substrates with Film Patterns
Authors: Fischer A. , Bloch G.
Published: January 2007

Assuming a film‐edge induced stress in an isotropic crystal, the shear stress distributions in diamond‐type semiconductor substrates with film double edges are calculated. Using the formalism developed, absolute stress values can be determined to optimize the semiconductor technology.
Quantitative Phase Analysis of Mixtures Containing α‐, β‐Tungsten and WO2
Authors: Salewski W. , Kiessling F. M.
Published: January 2007

For incandescent lamp wire fabrication various powder metallurgical steps are necessary. The stepwise reduction of WO3 to the tungsten metal powder is one of these. During reduction chemical reactions take place under participation of doping elements (K, Si and Al) causing the structure of non‐sag wires. The origin of secondary β‐W like an indicator for the activity of dopings has been attributed importance. Therefore it has been developed a method for quantitative phase analysis of α‐W, β‐W, WO2 mixtures consisting of oxidation value determination to establish the WO2 content and X‐ray phase analysis for a quantitative separation of the α‐W and β‐W content. The influence of extinction effects caused by particle size has been investigated and it is proposed a correction method of the measured integral intensities as a function of half‐width of the (110) α‐W reflex. In regard of the obtained results the formation of the tungsten suboxide W3O has been excluded.
Dynamic Behaviour of Ferroelectric Liquid Crystalline Thin Layers in Electric Fields
Authors: Schiller P.
Published: January 2007

The direction of the spontaneous polarization of a thin ferroelectric liquid crystalline film can be switched up and down between two stable states by applying an electric field. This process is investigated theoretically using the elastic continuum theory of liquid crystals. There are found two reorientation mechanisms with different switching rates. The regimes of fast bulk switching and relatively slow domain wall motion are separated by a critical threshold field.
On the Bindings in VOm Phases
Authors: Schubert K.
Published: January 2007

The phenomenological plural correlations model permits to attribute to the intermediate phases of the mixture VOM bonding types (bindings) which indicate a low energy of the empirically found structures. In the phases various electron subsystems exist which contain lattice‐like spatial correlations, and when the corresponding cells are in energetically low commensurabilities (in harmonies) to the crystal and to one another then the phase becomes stable. A fundamental assumption of a binding analysis is the electron count being here V1,4,8O0,6,2. As a consequence the phases V8O, V16O3, and V7O4 consist of a tetra‐gonally deformed V(B1) partial structure with interstices partly filled by O atoms. The composition of a phase determines the electron concentrations in the subsystems, and these influence the harmony of the correlations in the binding (BFU2 for V16O3, e.g.). In VO, V13O16, V2O3, and V3O5 an essentially complete close packed partial structure of O accepts V into its octahedral interstices. Once more harmonies of electron correlations determine favourable bindings (FF'2 for VO e.g.). The Magnéli phases V4O7 up to V8O15 being shear homeotypes of VO2 · h may be considered as homeodesmic to TiO2 · r, which is stabilized by a CFU2 binding. From the binding it may be concluded how much Hund insertion is present in a phase. Hund insertion is for instance responsible for the transformation VO2 · h → r. The phases V6O13, V4O9 and V3O7 are homeotypic to V2O5. This last phase permits presumably a UHT3 binding. The results of the binding analysis of VOM shed some new light on the interpretation of properties of the VOM phases.
Rolling Textures Predicted by the Elasto‐plastic Self‐consistent Model
Authors: Wierzbanowski K. , Ahzi S. , Hihi A. , Berveiller M.
Published: January 2007

The rotation rate fields of a f.c.c. polycrystal deformed by rolling have been predicted by the self‐consistent model for different values of the plastic accomodation parameter. The isotropic as well as anisotropic hardening of slip systems have been taken into account. The obtained rotation rate fields have been applied next to the continuity equation of texture evolution. All the results may be classified into two groups: a copper type texture and a transition texture (probably towards the brass type one).
Dry Patterning of Al and Al Alloys
Authors: Sameith D. , Tiller H.‐J. , Breitbarth F.‐W.
Published: January 2007

Plasmachemical etching of Aluminium in chlorine containing discharges is discussed from a thermochemical point of view. A model of Al etching is proposed, in which diffusion of reaction products through the carbon‐rich deposite layer is considered to be rate‐limiting. The model quantitatively describes the dependence of the etch reaction on different process parameters of the CCl4‐plasma.
SixGe1−xGaAs Heterojunction IMPATT‐Diodes
Authors: Brailovskii E. J. , Matveeva L. A. , Meľnikov G. D. , Mikhailov J. F. , Semenova S. N. , Tkhorik J. A. , Khazan L. S. , Laichter V. , Červenák J.
Published: January 2007

Experimental research IMPATT‐diodes on heterostructures SixGe1−x‐GaAs showed that the interphase boundary is noted with high thermal and radiation resistance. It is shown that such diodes are an equivalent alternative IMPATT‐diodes with type of Schottky barrier.
Investigation of Acoustic and Optical Properties of Ferro‐ and Piezoelectrics by the Optoacoustic Method
Authors: Golenishchev‐Kutuzov V. A. , Migachev S. A. , Rez J. S.
Published: January 2007

A review of applications of optoacoustic methods, based on the pulse laser generation of the ultrasonic waves in samples studied is given. The paper demonstrates the possibilities of this method in determine the elastic, photoelastic, piezoelectric constants, optical quality and damage stability of ferro‐ and piezoelectrics.
Geometrical Aspects of the Patterns of Conduction Paths in Fast Ion Conductors
Authors: Fischer W.
Published: January 2007

A method for a straightforward calculation of geometrically privileged conduction paths in fast ion conductors is presented. It makes use of a special property of Dirichlet domains, namely that their vertices and edges define all polyhedral voids and all least narrow connecting passages within a rigid framework. The results of the procedure are exhaustive in the geometrical sense and may be used as a basis for physical investigations. The method is illustrated by two simple examples, α‐AgI and sodium β‐alumina. Restrictions are discussed.
Photoluminescence from Thermally Treated CaO Single Crystals
Authors: Garcia J. A. , Remon A. , Piqueras J.
Published: January 2007

Photoluminescence emission and excitation spectra of CaO single crystals change strongly by annealing in air while rapid quenching does not produce new bands. The increase of an excitation band at 340 nm and the shift of the emission peaks are the main annealing effects observed. These changes, which are reduced by increasing the crystal thickness, have been found to be localized in the surface.
Stoichiometry of Thin Layers of CuInSe2 Investigated by ESCA
Authors: Sommer H. , John W. , Meisel A.
Published: January 2007

The stoichiometry of thin epitaxial layers of CuInSe2 on CaF2 and GaAs substrates was determined by the ESCA method. Substrate temperature was varied. It was found, that layers of exact stoichiometry are got at substrate temperatures around 700 K.
The Effect of Additions of Mn and Fe on the Structure of an Al‐2 at.% Zn‐1 at.% Mg Alloy
Authors: Löffler H. , Korngiebel E. , Dutkiewicz J. , Salawa J.
Published: January 2007

The structure of an Al‐1.9 at.% Zn‐1.3‐at.% Mg mother alloy with additions of Mn and Fe, respectively, were investigated by TEM and microprobe analysis for two different heat treatments, namely direct quench from 490 °C to 160 °C and a two‐step ageing treatment (preageing at RT for 7d before storing at 160 °C), to explain the differences in the course of the hardness obtained during the ageing at 160 °C. The differences of the structure observed are explained in terms of the tendency of the additives to form intermetallic phases, particularly in the grain boundaries.
Dissolution Kinetics and Etch Pit Morphology of CaF2 Single Crystals
Authors: Nicoarǎ I. , Aczel O. F. G. , Nlcoarǎ D. , Schlett Z.
Published: January 2007

The effect of temperature and concentration of HCl aqeous solutions on the etching behaviour on the face {111} of CaF2 single crystals is investigated. It has been observed that the shape and the evolution of etch pits and the values of dissolution rate depend on the etching conditions. From the plots of logarithm of dissolution rate versus inverse of absolute temperature the values of activation energy and the pre‐exponential factor for the dissolution process are computed. It has been found that the value of the activation energy and of the pre‐exponential factor do not remain constant with acid concentration, but exhibit a minimum for the concentration of 6 N.
The Dimer Association of Stearic Acid in Solution
Authors: Garti N. , Sato K. , Schlichter J. , Wellner E.
Published: January 2007

The dissociation constant of stearic acid was determined in four different solvents, using the Fourier Transform Infrared technique. The ΔH values obtained for each solvent decrease as the solvation of stearic acid increaes. The results are relevant to the crystallization process of stearic acid from solution which may lead to different polymorphic forms depending on the different crystallization parameters.
The Effect of Solid and Liquid Inclusions on Morphology of Crystallization Front
Authors: Ovsienko D. E. , Fedorov O. P. , Kiriyevsky B. A. , Gershtein G. I. , Chemerinsky G. P.
Published: January 2007

The interaction between crystallization front and solid particles was studied for substances characterized by the normal growth mechanism (continuous growth). It has been measured the critical velocity below which the particle of radius R is repulsed by moving interface and above it is captured. It has been shown that critical velocity is proportional to R−(1.4–1.8) what satisfactorily agrees with Chernov‐Temkin's theory. Data have been received about change of interface morphology at capture of solid particles for growth from pure and impurity‐contained melt. The dendrites have been found to split at interaction with particles and concentration inhomogeneities. Taking for example Al‐Cu alloy, possibility has been shown to disperse the dendritic structure by formation concentration inhomogeneities in the melt.
Determination of Molar Ratio in AB1−x Rocksalt‐type Compounds by X‐ray Powder Diffraction Method. Application to TiC1−x
Authors: Čapková P. , Karen P. , Dobiášová L.
Published: January 2007

The B/A molar ratio in AB1−x rocksalt‐type compounds is determined by X‐ray powder diffraction method by measuring of integrated intensities Ihkl. The strategy of measurement is presented to avoid all effects influencing the integrated intensities of X‐ray powder diffraction as primary extinction, preferred orientation and surface roughness effect. This paper deals with application of this method to the determination of the deviation from stoichiometry of TiC1−x compounds.
Burgers Vectors of Dislocations in Creep‐deformed Fe3Si Single Crystals
Authors: Krämer U. , Oertel C. G. , Zies G. , Kleinstück K.
Published: January 2007

In creep‐deformed Fe3Si single crystals the Burgers vectors of the dislocations were examined by transmission electron microscopy. The Burgers vector in a sample deformed under conditions of 60 MPa and 575–600 °C was of the type 1/2 〈110〉, whereas 〈111〉 superlattice dislocations were not found. 1/2 〈110〉 is the shortest translation distance in the D03 superlattice structure of Fe3Si.
Phase Transition Studies of the Liquid Crystal Pentyloxybenzylidene Phenylazoaniline
Authors: Rao K. R. K. , Rao J. V. , Venkatacharyulu P. , Baliah V.
Published: January 2007

Phase transition studies of the liquid crystal pentyloxybenzylidene phenylazoaniline are investigated with density and ultrasonic velocity measurements. The density variation with temperature confirms that the isotropic liquid‐nematic, nematic‐smectic A and smectic A‐smectic B transitions are of first order. The temperature variation of ultrasonic velocity confirms all the phase transitions. The adiabatic compressibility (βad), Rao number (Rn) and Molar compressibility (B) are estimated from density and ultrasonic velocity.
Thermoelectric Power of Sb2Te3 Films
Authors: Moorthy P. A. Krishna , Shivakumar G. K.
Published: January 2007

The thermoelectromotive force of vacuum deposited Sb2Te3 films on glass substrates has been measured by the integral method in the temperature range 30–250 °C. The film thickness varied between 1200–9600 Å. Thick antimony pads evaporated onto the sample at both ends served as contacts. The thermoelectric power (α) is found to be positive and increases with temperature for thinner samples and at higher temperatures a steady value is achieved. Further increase in the temperature decreases the thermoelectric power. When the film thickness is increased, α decreases. This is explained as due to the reduction in intercrystalline barrier at elevated temperatures and at higher film thicknesses.
Heights of Overlapping X‐ray Reflections and Phase Analysis
Authors: Valvoda V.
Published: January 2007

The influence of reflections overlapping on the heights of their maxima is investigated using the Lorentzian profile approximation. This influence should be taken into account in automatic powder diffractometer programs of phase analysis based on the peak heights.
Specific Heat and Lattice Anharmonicity in ZnSiP2 and ZnSiAs2
Authors: Neumann H. , Kühn G. , Möller W.
Published: January 2007

The molar specific heat at constant pressure was measured for ZnSiP2 in the temperature range from 300 to 400 K and for ZnSiAs2 from 300 to 500 K. An analysis of the experimental data showed that the contribution to the specific heat due to lattice anharmonicity can be described by a polynomial of third order in the temperature. Predictions are made regarding the expected temperature dependence of the thermal expansion coefficients and compared with existing experimental data.
Vibrational Properties of LiGaO2(I). Experimental Results
Authors: Neumann H. , Kissinger W. , Neels H. , Riede V. , Sobotta H.
Published: January 2007

Infrared reflectivity spectra of LiGaO2are measured at room temperature in the wave‐number range from 200 to 4000 cm1for the polarization directions E ∥ a and E ∥ c. The parameters of 10 B1modes and 4 A1modes are determined by a dispersion analysis of the spectra. The results obtained are compared with previous Raman scattering measurements.
Influence of γ‐Irradiation on Some Properties of NaCl: Eu++ Crystals (I). Optical and Dielectrical Characteristics of the Dopant Ions
Authors: Suszynska M. , Opyrchal H. , Nierzewski K. D. , Macalik B. , Gubanski A.
Published: January 2007

The present work opens a series of papers describing a variety of properties of the same material, and deals with the effect of Eu++ ions, and y–irradiation on the optical and dielectrical characteristics of NaCl crystals. For nonirradiated crystals four types of Eu++‐related absorption spectra have been identified and correlated with I.V. dipoles and three types of precipitates stable in the well aged crystals. For the solution—treated samples the effect of irradiation was to diminish the concentration of I.V. dipoles and to change the absorption spectrum in a remarkable way. These changes are explained in terms of the formation of some dopant—related clusters different of those obtainable thermally. No spectroscopic evidences have been obtained for the radiation—induced changes of the valence state of the dopant irrespective of its dispersion degree.
Nature of the Maximum Microsegregation of Binary Alloys from Peritectic Phase Systems
Authors: Wołczyński Waldemar
Published: January 2007

A value of the distribution coefficient is of a significant importance for the microsegregation phenomenon. Moreover, the nature of the microsegregation is due to a given phase system, and the Sb–30 Sn alloy has been set as an example to show the maximum microsegregation which can form during solidification of this alloy. A new relation, supplementary to the Scheil equation has been proposed.
An X‐ray Diffraction Refinement of the Crystal Structure of Natural Stellerite, Ca(Al8Si28)O72 · 28 H2O
Authors: Pechar F. , Mattern G.
Published: January 2007

An X‐ray diffraction analysis was performed on a single crystal of natural stellerite, (Ca3.59Na0.35K0.05Mg0.06)tot.=4.05 (Al7.88Fe0.09)tot.=7.97Si28.02O72 · 38.25 H2O, orthorhombic, Fmmm, a = 13.625(2) Å, b = 18.284(1) Å, c = 17.850(2) Å. Z = 4, V = 4446.77 Å3. Refinement of 1400 independent reflections yields R = 0.0429 (Rw = 0.0479). The Si(Al)O bond distances are determined with a precision of 0.002‐5 Å. The framework of stellerite is topologically the same as stilbite 4–4–1.
Crystal and Molecular Structures of Modified Progestagens (I). 17α‐Cyanomethyl‐17β‐hydroxy‐estr‐4‐en‐3‐one, C20H27NO2
Authors: Reck G. , Hübner M. , Bohl M. , Bannier G. , Kretschmer R.‐G.
Published: January 2007

17α‐Cyanomethyl‐17β‐hydroxy‐estr‐4‐en‐3‐one is the first member in a series of progestagens investigated systematically by X‐ray structure analyses. It crystallizes in the orthorhombic space group P 212121 with cell parameters α = 8.887(6), b = 11.814(7), and c = 16.263(2) A. The structure was solved by MULTAN‐82 and refined to R = 0.045 for 1453 observed reflections. The steroid ring A has an 1β‐sofa conformation, the rings B and C adopt chair forms, ring D is intermediate between 13β,14α‐half chair and 13β‐envelope. All rings are trans‐fused. In the present structure, OH… N hydrogen bonds link the molecules into chains parallel to α.
Residual Stress Fields in Cylindric Bridgman‐Stockbarger Crystals of Fluorite
Authors: Dressler L.
Published: January 2007

Relationships between the residual stress fields in fluorite and the regime of temperature during the crystal growth have been examined. Beside heat conduction the internal heat transfer in the growing crystal by radiation is important, and therefore an effective anisotropy of heat transfer properties in axial and radial direction exists.
The Use of an Electrode Potential in the Investigation of a Single‐Crystal Semiconductor Matrix (II) Anisotropy of Surface Damages in Silicon Single Crystal Cutting
Authors: Gulidov D. N. , Aidelman B. L. , Yu. Charlamov V. , Chistyakov Yu. D.
Published: January 2007

Anisotropy of the depth of surface damages in cutting of single crystal silicon along (111) plane by ID saw is investigated due to electrode potential technique. The reasons of appearance of azimuth and planar anisotropy depending on cutting rate directions are shown. In the cutting rate change in the range of 25–100 mm/min doesn't result in the change of azimuth anisotropy character. It is only abrasive action vector that is supposed to be responsible for the appearance of azimuth anisotropy.