bluuebunny/crossref_metadata_2025_split huggingface dataset:
Infrared photoluminescence ‐ a tool for HgCdTe crystal research
Authors: Tomm J. W. , Schmidt H. , Werner L. , Herrmann K. H. 
Published: January 2007

AbstractMaterial and structural parameters of narrow‐gap p‐type HgCdTe are investigated by infrared photoluminescence. The method is used for analyzing the energy gap, the carrier lifetime, and heterointerfaces and to monitor defects like inclusions. The spatial distribution of the quantities mentioned has been investigated by applying the mapping technique known for III – V semiconductors. The methods is a powerful tool for both crystal growth and device manufacturing.
Three X‐ray diffraction methods for testing of large disk‐shaped or lentiform CaF2‐crystals for high‐performance optics
Authors: Dressler L. , Kafka F. , Krässlich J. , Wehrhan O. 
Published: January 2007

AbstractThree methods (Lang‐topgraphy, one‐crystal‐rocking curves with scan‐step‐registration, two‐crystal‐diffractometry (TCD) with a large registered area) were tested. The reached parameters as well as advantages and disadvantages are discussed. The purpose of the examination is the application of CaF2‐crystals with high diameters (⪆ 100 mm) in high‐performance optics for the UV‐lithography. Especially in this context the influence of defects of the crystal structure on the index of refraction has been examined.
Origin of defect centers in multilayered GaInAs and their influence on photoluminescence spectra
Authors: Popov A. S. , Ivanova E. A. 
Published: January 2007

AbstractThe one‐, two and three‐layered GaInAs structures grown on GaAs substrates by LPE have been investigated. The luminescence analysis with HeNe laser‐beem excitation and crystal diffractions were used for characterization of the structures. It was established that the thickness of the first layer has an optimum, below which the influence of structural defects is considerable.
Comparative Photoemission Study of the CuInC Chalcopyrite Compounds
Authors: Sommer H. , Weiss A. , Neumann H. , Tomlinson R. D. 
Published: January 2007

AbstractPhotoemission spectra of all CuInC2VI chalcopyrite compounds are measured at Hel line excitation and of CuInS2 also at excitation with ZrMζ radiation. It is found that the In5s – chalcogen p bonding states shift to lower binding energies with increasing anion mass. The energetic position of the S3s band of CuInS2 is also determined. The experimental results obtained are compared with previous measurements and with theoretical band structure calculations.
Auger depth profiling of BaTiO3 ceramics
Authors: Berndt K. , Rammelt B. , Heichler S. C. W. 
Published: January 2007

AbstractWe investigated the sputter depth profiling of BaTiO3 by means of Auger Electron Spectroscopy. A quantitative analysis was done for ceramic and single crystal material. Sputtering yield for 2 and 3 keV Ar+ ions was determined. For under UHV conditions fractured specimens no preferential sputtering was found. Mechanically polished or contaminated ceramic specimens show preferential sputtering of Ba or Ti. Using sputtering – heating cycles we succeeded in preparing non‐contaminated but ion beam mixed surfaces which are stable upto 150 °C.
General classification of crystalline materials used in modern technology
Authors: Brekhovskikh S. M. , Rez J. S. 
Published: January 2007

AbstractScientific bases of the general classification of crystalline materials such as single crystals, polycrystalline materials and glass ceramic have been expounded. In the systematic procedures the materials are signified by the applicability formulas. Materials belonging to the certain taxons as well as their ability to carry out some official functions under the given conditions of the relationship with the factors of the environment are also determined by the applicability formulas.
Diode n‐p CuInSe2 Structures Fabricated by Oxygen Implantation
Authors: Medvedkin G. A. , Yu. Rud V. , Yakushev M. V. 
Published: January 2007

AbstractThe influence of oxygen implantation on the electrical features of n‐type CuInSe2 single crystals has been studied. n‐p type conversion in the implanted region has been observed. Photoelectric characteristics of the fabricated structures have been examined. It has been shown that ion implantation allows to fabricate CuInSe2 photoconverters with the absolute current sensitivity up to Si = 33 mA/W at 300 K.
X‐ray powder diffraction and Raman spectroscopy studies of phase transitions in zinc(II) hexaaquonitrate below 300 K
Authors: Borzęcka‐Prokop B. , Kapturkiewicz E. , Weselucha‐Birczynska A. , Hodorowicz S. A. 
Published: January 2007

AbstractStructural phase transitions in zinc(II) hexaaquonitrate have been studied below 300 K by Raman spectroscopy and X‐ray powder diffraction. Changes of A1 nitrate and OH bands together with diffractograms as functions of temperature are presented. The compound undergoes several transitions and four previously unreported modifications were found and characterized.
Empirical relationship between hall mobility and hole concentration in heavily doped p‐type GaAs
Authors: Neumann H. 
Published: January 2007

AbstractUsing Matthiessens' rule and assuming a constant mobility contribution due to lattice scattering an empirical relation is derived for the Hall mobility at room temperature in p‐type GaAs as a function of the hole concentration in the range from 1018 to 1020 cm−3. The resulting empirical concentration dependence of the mobility due to ionized impurity scattering is compared with the Brooks‐Herring formula. The degree of compensation of p‐type GaAs liquid phase epitaxial layers doped with germanium is estimated from the measured Hall mobility and compared with corresponding data obtained from an analysis of the temperature dependence of the hole concentration.
Preparation and optical absorption properties of one‐dimensional organic electron conductors
Authors: Robles‐Martínez J. G. , Salmerón‐Valverde A. , Soriano C. , Alonso E. , Zehe A. 
Published: January 2007

AbstractA series of metal containing organic compounds of the M[HNAFIN]2 · 2TCNQ‐type, being M either Ni, Pd, Pt, Cu or Zn, have been prepared and studied in respect to infrared absorption spectra. Characteristic IR absorption spectra for each of the compounds are manifest, depending on the nature of the metal introduced. In particular is the C  N stretch mode absorption spectrum for Ni‐containing compounds rather sharp and single peaked, while Pt and Zn containing compounds present more complex features.
Growth and microhardness studies of melt‐grown lead (II) chloride single crystals
Authors: Sagayaraj P. , Sivanesan S. , Baskar K. , Gobinathan R. 
Published: January 2007

AbstractIn the present work, lead (II) chloride material is purified by directional solidification and single crystals of PbCl2 are grown by vertical Bridgman technique employing double zone furnace. The growth conditions and the problems overcome are discussed. The grown crystals of pure and K+‐doped crystals are cleaved and subjected to microindentation tests. The validity of Kick's relation is checked, the value of K1 the standard hardness number and n the work‐hardening coefficient are discussed. The microhardness behaviour of pure and K+‐doped lead(II) chloride have been compared.
Preparation and fundamental physical properties of Sn2SbS2I3 and Pb2SbS2I3 compounds
Authors: Starosta V. I. , Kroutil J. , Beneš L. 
Published: January 2007

AbstractThe oriented ingots of isostructural compounds Sn2SbS2I3 and Pb2SbS2I3 were prepared using a modified Bridgman method. The lattice parameters of the prepared orthorhombic compounds have been determined by a X‐ray powder diffraction analysis. From the spectral response of the photoconductivity the following values for the forbidden zone of the prepared sulfides‐iodides were found: Eg(Sn2SbS2I3) 1.5 eV, Eg(Pb2SbS2I3) = 2.0 eV.
Influence of the Curvature Dependence of Interfacial Energy on Homogeneous Nucleation Kinetics
Authors: Kožíšek Z. 
Published: January 2007

AbstractInfluence of the curvature dependence of surface tension on nucleation rate and cluster distribution function is studied. When the curvature dependence of the interfacial energy of a cluster, σ, is taken into account the number of monomers decreases, in contrast to the case when σ = const. Decrease of monomers caused the decrease of nucleation rate.
Effect of Buoyancy‐driven Convection on Surface Morphology and Macromorphology of Potassium Bichromate Crystals
Authors: Szurgot M. 
Published: January 2007

AbstractSurface topography and macromorphology of potassium bichromate crystals grown from unstirred aqueous solution depend on diffusion and convection. Micromorphology of as‐grown surfaces is a source of quantitative data on the local values of the degree of supersaturation σ at various parts of crystals. Micromorphology and values of growth velocities of faces, differently located in space with respect to the gravitational force show that upper parts of the crystals grow at about 5–25% lower values of σ than the lower ones. The cause of convection changes of size and number of faces is the characteristic distribution of supersaturation around the crystal induced by movement of the solution.
X‐Ray Characterization of Guanidine Aluminium Sulfate Hexahydrate Crystals in Relation to their Ferroelectric Properties
Authors: Robert M. C. , Lefaucheux F. , Le Bihan R. , Rafii N. 
Published: January 2007

AbstractCharacterization of growth defects by X‐ray topography of Guanidine aluminium sulfate hexahydrate crystals allows to set a close correlation between ferroelectric domain and growth sector patterns. The crystalline quality of prismatic sectors is much better than that of basal sectors.
On the Fit between Precipitates and Matrix in Al–Zn Alloys
Authors: Löffler H. , Ramlau R. 
Published: January 2007

AbstractThe quality of the fit between the precipitates occurring in Al–Zn alloys and the matrix of the Al host is considered taking into account the positions of the atoms in the lattice planes forming the possible faces of the precipitates and the neighboured lattice planes of the matrix. The quality of the fit depends on the number of (pseudo‐)coincidence sites of both planes, the density of Al atoms in the matrix plane and the misfit in the spacings of the atoms in the adjoining planes in consideration. The effect of the misfit is taken into account by means of two different models. Based upon the obtained results many of the experimentally observed features about the preferred shapes and orientations of the faces of the growing precipitates can be explained. It turned out that in both of the applied models most probably the effect of the density of the coincidence sites on the interfacial energy is underestimated.
Studies and Characterisation of Some Nd Laser Glass Rods Using Different Q‐Switching Techniques
Authors: Ghosh P. S. , Ghosh N. P. , Bhattacharya S. , Samanta L. K. 
Published: January 2007

AbstractUsing various Q switching techniques the performance potential of some Nd: glass rods have been analysed and compared with that of a standard rod. Second harmonics generated from such a Q‐switched system have been separated from the fundamental using suitable dispersive element.
Low‐temperature Thermoluminescence Glow Curves in NaCl Crystals Doped with Yttrium
Authors: Reddy Ch. Gopal , Reddy K. Narasimha , Reddy M. Mutha 
Published: January 2007

AbstractThermoluminescence glow curves were recorded in undoped and yttrium‐doped NaCl crystals X‐irradiated at liquid nitrogen temperature (LNT). An attempt is made to assign the glow peaks observed to different centres such as Vk‐centres and yttrium related centres etc.
Elastic and Thermoelastic Properties of the Twinned Perovskite LaGaO3 and the Cubic Untwinned Perovskite La0.294Sr0.706Al0.647Ta0.353O3
Authors: Haussühl S. , Mateika D. 
Published: January 2007

AbstractThe elastic and thermoelastic constants of twinned crystals of LaGaO3 and untwinned crystals of La0.294Sr0.706Al0.647Ta0.353O3 have been measured by ultrasonic resonance methods. Both materials exhibit a quite similar elastic behaviour characteristic, as for perovskites. Employing a simple formula for ionic crystals, the elastic constants of both oxygen perovskites reveal a depression of about one third in comparison to the fluor perovskite LiBaF3.
Infrared Optical Characterization of Thermally Oxidized CuInSe2 Single Crystals
Authors: Sobotta H. , Neumann H. , Tomlinson R. D. , Riede V. 
Published: January 2007

AbstractInfrared reflectivity spectra of thermally oxidized CuInSe2 single crystals are measured at room temperature in the wavenumber range from 180 to 4000 cm−1. A Kramers‐Kronig analysis of the spectra reveals seven vibrational modes with frequencies which agree with mode frequencies in In2O3. No vibrational modes due to Cu–O and Se–O bonds could be observed. The results obtained are compared with previous studies of oxidized CuInSe2 crystals.
Measurement of Temperature Fields and Convection in a Eutectic Melt(I). Influence of Ampoule and Insert Shape on Temperature Field of an AIZn Eutectic
Authors: Holeček S. , Procio M. , Pražák M. , Kubíček L. 
Published: January 2007

AbstractA study has been made of the temperature field in an AlZn eutectic melt for a Bridgman‐Stockbarger arrangement of the experiment. The influence of the sizes of the ampoules and corundum inserts for the temperature measurements on the final temperature field in the specimen has been studied for different angles α contained by the gravity and the axial temperature field gradient vectors in the specimen. It has been found that an axially located corundum insert increases the convection intensity to a maximum at angles α between 45 and 60°. An influence of the insert for α = 0° is almost negligible.
Kinetics of Dissolution of Calcium Oxalate Calculi in Physiological Solutions Containing Hippuric Acid
Authors: Gutzow I. , Atanassova S. , Budevsky G. 
Published: January 2007

AbstractAn analysis of the thermodynamics and kinetics of crystal growth and dissolution of slightly soluble salts in physiological solutions in the presence of complexing ions is made, accounting for conditions typical in human urine. It is found that hippuric acid, a normal physiological constituent of urine, acts at increased concentrations as a dissolving agent with respect to calcium oxalate and calcium oxalate calculi. The kinetics of dissolution of crystalline calcium oxalate calculi (CaOx) in physiological solutions containing hippuric acid in different concentrations is studied, using the change in the Archimedean weight of samples, immersed in the solution.The analysis of the experimental results enables the determination of the increased solubility of CaOx in the presence of hippuric acid and to characterize quantitatively this substance as a new and very prospective dissolving agent of CaOx calculi in human urine. A discussion is also given on the possible effect of hippuric acid as a neutral regulator of CaOx‐supersaturation and crystallization in human and mammal urine.
Investigations into Phase Formation of Decomposed Ni0.5Zn0.5Fe2(C2O4)3 6 H2O Solid Solution Oxalates
Authors: Fischer S. , Langbein H. , Michalk C. , Knese K. , Heinecke U. 
Published: January 2007

AbstractHomogeneous solid solution oxalates of Ni(II)‐, Fe(II)‐ and Zn(II) were prepared by coprecipitation from metal acetate solution with oxalic acid. Using Mössbauer spectroscopy, XRD, magnetic measurement and IR‐spectroscopy, the thermal decomposition of Ni0.5Zn0.5Fe2(C2O4)3 · 6 H2O and the formation process of Ni0.5Zn0.5Fe2O4 were investigated.At temperatures between 300 and 400 °C the thermal decomposition of the Ni–Zn–Fe solid solution oxalates leads to ferrites of spinel structure, but areas with a different content of Ni and Zn are provable by Mössbauer spectroscopy. After tempering at 750 °C homogeneous ferrites arise.
Solid Inclusions in Man‐made Quartz Crystals Electron Microscopic Investigation
Authors: Kirov G. K. , Neykov H. N. 
Published: January 2007

AbstractShort‐term hydrothermal experiments were carried out for a more detailed study of solid inclusions in man‐made quartz crystals. In these experiments the crystals which usually are included in quartz occur on the surface of the seed and are only partly overgrown by quartz. Optical observations and SEM and EDS investigations have shown that: 1. The formation of inclusions is a special event in the history of autoclave growth of quartz, the process being controlled by the formation of many sites of increased surface tension. 2. Epitaxial phenomena are of great importance in the formation of inclusions. 3. The solid inclusions are of quartz (30%) and of the Na‐Fe‐silicate Phase 1 (70%). Both occur as single crystals larger than 3 μm as well as clusters of crystals smaller than 2 μm. 4. The several other phases observed as inclusions are of no importance for the quality of the man‐made quartz crystals.
Phase Equilibrium in the System HgSeO4 – H2SeO4 – H2O at 100°C
Authors: Gospodinov G. , Barkov D. 
Published: January 2007

AbstractThe solubility of the system HgSeO4 – H2SeO4 – H2O was studied at 100 °C. The fields of crystallization of HgSeO4 H2O and HgSeO4 were established. The compounds obtamed were identified by means of chemical, X‐ray and crystal‐optical analysis. The mechanism of the thermal dissociation of the compounds obtained was studied.
To the Unified Model of Condensed State
Authors: Vlasov A. D. , Rez J. S. 
Published: January 2007

AbstractThe problem of unified model of condensed state can be solved by using solid‐like model of liquids. A liquid arises when in a heated crystal a universal process of microcrack formation takes place that leads to originating a great number of very small crystals: microcrystallites. In the paper the two basic notions: the effective temperature of crystal surfaces and the internal thermal stresses in crystals are discussed. These notions make possible the microcrystallite model of liquids and the unified model of condensed state. Thus, the microcracks, resulted from thermal stresses, below the melting point lead only to decreased strength of crystals but above melting point the microcracks are spread all over the crystal bulk and cause splitting of the crystal into microcrystallites that are moving freely, in short, making up a liquid. The simple relations for these processes are given. In the end of the paper the identical features of the condensed states, solid and liquid, has been considered.
Texture of Y‐ and Bi‐HTSC and Methods for its Determination
Authors: Shamray V. F. , Babareko A. A. , Efimov Yu. V. , Frolova T. M. , Myasnikova E. A. 
Published: January 2007

AbstractInvestigation of the texture of Y‐ and Bi‐HTSC materials by X‐ray techniques involves certain difficulties owing to the peculiarities of their crystal structure which causes the arrangement of reflexes in dense groups and practically precludes the formation of a pole figure from an isolated reflex. The texture of Y‐ and Bi‐HTSC materials has been investigated by constructing direct pole figures in an automatic texture diffractometer DAPT YM 1 in CuKα emission from groups of reflexes which are unresolvable under the test conditions. The choice of groups of reflexes was dictated by the type of texture formed. With a basal texture of packing of powders, the following groups have turned out to be the most suitable for the YBa2Cu3O7–x phase (123): (013) + (110) + (103), 2θ = 32.3 – 32.8º and (014) + (005) + (104), 2θ = 38.5 – 38.8º. They include the reflexes which are structural and superstructural relative to a bcc subcell with a rather slight orthorhombic distortion, with its tripling along the “c” axis forming a cell of (123) compound. For the Bi2Sr2CaCu2O8 phase, there have been used the groups of reflexes (008) + (111) + (1.4/54), (0.0.10) + (1.6/5.4) + (0.9/5.1), (0.0.12) + (1.6/5.8) + (204) + (119). (115) + (1.6/5.4) + (0.1/5.9), and (117) + (0.9/5.1) + (1.6/5.6) + (1.4/5.8), 2θ with respectively 23.2 – 24.0º, 29.1 – 29.7º, 35.1 – 35.2º, 36.5 – 28.4º, and 29.7 – 31.4º. They also include reflexes from the lattice constructed by multiplication of a perovskite cell with α = 5.40 Å, b = 5.41 Å and c = 30.6 Å along the “b” axis. Y‐HTSC‐based materials also contain a component of shear texture which is close to such a texture in bcc metals. The texture of Y‐ and Bi‐HTSC materials is relatively stable in hightemperature annealing. The nature of the effect of annealing at moderate temperature is different.
Infrared Absorption Spectra of CdIn2Te4
Authors: Riede V. , Neumann H. , Krämer V. , Kittel M. , Sobotta H. 
Published: January 2007

AbstractTransmittance and reflectance spectra of CdIn2Te4 are measured in the wavenumber range from 200 to 4000 cm–1. In the range from 200 to 400 cm–1 the spectra are governed by two‐phonon combination mode absorptions. In the wavenumber range above 400 cm–1 absorption coefficients below 1 cm–1 and a constant reflectivity of about 0.21 are found.
A Direct Method for Orientation Determination Using TEM (I). Description of the Method
Authors: Möck P. 
Published: January 2007

AbstractA new method for orientation determination has been developed. The orientation of crystals of a high symmetry (especially cubic crystals) can be determined immediately while working on the transmission electron microscope (TEM). For the application of the method the TEM must be equipped with a specimen‐tilt goniometer. By tilting the specimen the angles of the stereographic projection are obtained from no more than two easily identified Kikuchi poles on the screen. The stereographic projection can be constructed from these angles. The indices of the crystal orientation direction (and any other lattice direction) can be calculated from the angles between this direction and the base vectors. These angles can be measured using a Wulff net in the stereographic projection of the transmitted crystal.
Synthesis of BaCuO2 by Different Ways
Authors: Krüger Ch. , Reichelt W. , Lubahn U. , Scheler H. , Oppermann H. 
Published: January 2007

AbstractIn order to optimize the synthesis of BaCuO2, different modes were developed and estimated. Wet chemical powders produced by coprecipitation of oxalates or hydroxycarbonates were characterized and their reactivity is compared with the conventional ceramic process of firing a mixture of BaCO3 and CuO by DTA, XRD and IR‐investigations.This becomes possible, because the decomposition of these chemical precursors to BaCO3 and CuO is finished up to 600 °C. Hence, the same reaction for the formation of BaCuO2 is monitored.
Growth of Single Crystals of Calcium Sulfite in Silica Gels
Authors: Patil S. N. , Rao A. Venkateswara 
Published: January 2007

AbstractThe paper reports on the growth of single crystals of calcium sulfite, CaSO3 0.5 H2O, by reaction of aqueous solutions of CaCl2 and Na2SO3 in silica gels. Na2SO3 incorporated gels give spherulites whereas CaCl2 incorporated gels give transparent single crystals. The morphology of the crystals depends on the region of the gel and the type of reactant incorporated into the gel‐forming solution. Initially formed precipitate and dendrites are converted into good quality single crystals by dissolution and recrystallization processes.
Kinetics of Non‐isothermal Overall Crystallization in Polymer Melts
Authors: Dobreva A. , Gutzow I. 
Published: January 2007

AbstractA simple formalism describing the non‐isothermal crystallization kinetics in cooling runs at small undercoolings is suggested. A general mathematical method for analyzing processes of non‐isothermal phase formation, accounting for the proper temperature course of the nucleation rate and of the linear growth velocity is developed. It allows analytical description of cooling or heating DSC or DTA experiments in the whole range of possible crystallization temperatures.The results of the theoretical analysis at small undercoolings are compared with the measurements performed with a number of polymer melts and a satisfactory agreement between theory and experiment is observed.