bluuebunny/crossref_metadata_2025_split huggingface dataset:
Properties of Doped GaSb Single Crystals Grown by the Czochralski Method
Authors: Šestáková V. , Štěpánek B. , Šesták J. 
Published: January 2007

AbstractThe specific electrical properties and average dislocation density of GaSb crystals are shown and discussed regarding various elements presented as dopant. The single crystals were grown by the Czochralski method without encapsulant in a flowing atmosphere of molecular hydrogen, on the one hand, and of atomic hydrogen, on the other hand. The results are summarized in the Table II.
Entropy Contribution and Stacking Fault Energy of CdI2 Polytypes
Authors: Khan Momeen, M. Y. 
Published: January 2007

AbstractThe CdI2 material when is grown by using the different techniques under a same growth conditions shows a rich character in crystallization with several phases (polytypes). The exhibition of these polytypes has been explained here by following the Gibb's phase rule. Therefore, an effort has also been made to calculate the stacking fault energy of these polytypes.
Operating Limits for Stable Growth of Silicon Fibers with Diameter Less Than 150 μm by Modified μ‐PD Method
Authors: Epelbaum Boris M. , Shimamura Kiyoshi , Uda Satoshi , Kon Junichi , Fukuda Tsuguo 
Published: January 2007

AbstractThe μ‐PD method originally developed for oxide crystals has been modified and applied for filamentary silicon crystal growth. Our main modification of μ‐PD method is concerned with an arrangement of melt permeable feeder which is inserted into the nozzle. The feeder finishes by a sharp tip the diameter of which (is almost the same as that of the desired semiconductor fiber, i.e., less than 150 μm. Silicon fibers were grown from the small liquid pool at the end of the feeder. Three types of crucible‐die arrangement were designed and tested. The best results were obtained with the help of inclined insert made of graphite fibers because of its ability to quench oscillations and longer operation life. Fiber crystals, 100 μm in diameter and 70 mm in length, have been grown successfully. Small meniscus stability, operating limits of μ‐PD method and silicon carbide formation during the growth process are discussed.
Meyer's hardness law and its relation to other measures of ball hardness tests
Authors: Berg Gunnar , Grau Peter 
Published: January 2007

AbstractThe force dependence of the ball indentation hardness can be described in many cases by MEYER's hardness law. The characteristic material parameters are the MEYER constant K and the MEYER exponent n. But often other simple measures of hardness are used for technical applications. Examples are the difference of hardness for two different loads, which gives a good view of the hardening capability of the material, and the BRINELL hardness.It is shown that empirical found relations between the mentioned measures of hardness and the MEYER parameters are strong consequences of the validity of MEYER'S law. In special ranges of the values of the material parameters these empirical relations are linear ones. As a result of the theoretical considerations one must recommend to use the theoretical relations to fit the experimental values, because only in this case all physical conditions are fulfiled automatically.
Modification of the CuInSe2 Crystal Surface during Polishing and Annealing
Authors: Yakushev M. V. , Neumann H. , Tomlinson R. D. 
Published: January 2007

AbstractThe RBS/channelling technique was used to study the near‐surface damage characteristics of CuInSe2 crystals after polishing with 0.05 μm grade alumina and subsequent annealing up to temperatures of 600 °C. A comparative RUMP and damage density depth profile analysis of the channelling spectra revealed a polish‐induced near‐surface disordered layer with a thickness close to 40 nm. Up to annealing temperatures of about 400 °C a gradual overall decrease of the defect density in the damaged layer is observed without detectable changes in its thickness. An indium‐rich surface layer is formed after vacuum annealing at 600 °C.
Certification of Reference Material with Special Emphasis on Porous Solids
Authors: Meyer K. , Klobes P. , Röhl‐Kuhn B. 
Published: January 2007

AbstractCertified reference materials (CRMs) are very important for the reliability of the results of chemical analyses and, at the same time, constitute the basis of comparability of analytical data. The development of a new type of CRMs is demonstrated using the example of porous and finely dispersed solids having specific surface area, specific pore volume, pore volume distribution, and mean pore radius as their characteristic values.Many of the properties of reference materials to be certified, such as their elemental content, are established by means of measurement procedures relying on different and independent principles of measurement. With porous or finely dispersed solids, however, the characteristic values referring to pores strongly depend on the size of the probe molecules used, a fact which is due to the fractal character of these substrates. This is particularly true for the specific surface area or the pore volume. As a result, when applying the method of gas adsorption, the certified values refer to a specific probe gas, e.g. to nitrogen. The use of other gases yields different numerical values for the characteristic values to be certified.Generally, the pore system of a solid contains pores of irregular shape. Therefore, depending on the presence of e.g. cylinder or slit pores, different evaluation models must be applied. For the verification of model calculation of microporous solids, zeolites with their crystallographically defined voids are particularly well suited. They can serve as a reference point for the correctness of the model used.
The modelling of irregular interstratified structures of single crystals with chemical inhomogeneity
Authors: Frank‐Kamenetskaya Olga V. , Ivanova T. I. 
Published: January 2007

AbstractThe possibilities of modelling of irregular interstratified structures of single crystals with chemical inhomogeneity are discussed: the theoretical basis, the requirements to the X‐ray experiment, the accuracy and reproducibility of the diffraction data, the reliability of the suggested models. The examples of the successful application of the approach to the study and description of the defect structures of single crystals belonging to different structural types are considered. Three general types of irregular interstratified structures differing in the nature of chemical inhomogeneity as well as in the peculiarities of their diffraction patterns are distinguished.
Polarity identification of GaN bulk single crystals (0001) surface by Auger electron spectroscopy
Authors: Iller Alicja , Marks Jerzy , Grzegory Izabela , Litwin‐Staszewska Elżbieta , Boćkowski Michal 
Published: January 2007

AbstractAn attempt to identify the polarity of (0001) polar surface of GaN bulk single crystals grown by high nitrogen pressure solution method has been made using Auger electron spectroscopy (AES). AES concentration depth profiles of the top layer in (0001) direction starting from both (0001) faces of the sample have been measured. Distinct difference in the Ga concentration at the sample surface of both faces has been observed. The dependence of Ga eoncentration on depth is also different for both faces of the sample.
CuxAg1–xGaS2 Solid Solutions
Authors: Bodnar I. V. 
Published: January 2007

AbstractCuxAg1–xGaS2 large‐scale blocks were obtained by two‐temperature synthesis method with the following crystallization of the melt. It was established, that crystal lattice parameters are changed according with Vegard's law, and microhardness have an extremum on the base DTA measurements state diagram of AgGaS2CuGaS2 system was built up. The composition dependence of band gap has nonlinear behaviour.
PVT and CVT Growth and Characterization of SnSxSe2‐x (0 ≤ x ≤ 2) Single Crystals
Authors: Patel D. H. , Patel R. G. , Arora S. K. , Agarwal M. K. 
Published: January 2007

AbstractSingle crystals of solid solutions of tin sulphoselenide have been grown in the same ampoule. Specific conditions for growing single crystals of SnSSe have also been identified. A study of microstructures on the growth surfaces responds to the mechanism of growth of these crystals. The dependence of electrical resistivity, Hall mobility and carrier concentration with the values of the configuration parameter 2 has been studied.
Crystal Structure of the Fibrillar Zinc Trimolybdate ZnMo3O10 · 3.75 H2O by Powder Diffraction Methods
Authors: Lasocha W. , Surga W. , Hodorowicz S. , Schenk H. 
Published: January 2007

AbstractThe crystal structure of polycrystalline fibrillar zinc trimolybdate ZnMo3O10 · 3.75 H2O, has been solved ab initio by the Powder Diffraction — Direct Methods package POWSIM. The structure was refined by the Rietveld method with final discrepancy factors RF = 11.0 and Rwp = 21.0%. The structure consists of polymeric chains parallel to the b axis built up of MoO6 octahedra. The space group is Immm (71) with a = 8.8330(6), b = 3.8207(4), c = 15.737(2) Å V = 531,08(6) Å3, Z= 2.
Anisotropic Surface Order in the Isotropic Phase of Nematic Liquid Crystals
Authors: Harthi Salim Al , George A. K. 
Published: January 2007

AbstractA spinning‐drop technique was used to study the thermal variation of surface tension of two nematic liquid crystals at the interface with an isotropic fluid. A sharp increase in interfacial tension was observed in the vicinity of the nematic‐isotropic transition. The interfacial tension‐temperature characteristics, unlike monotonically decreasing dependence found in most isotropic fluids, showed regions of positive slope, both in the isotropic and anisotropic phases. A positive slope in the isotropic region of the liquid crystal is interesting since it implies that excess order has developed at the surface while the buk interior remains isotropic.
On the curious structural phases in Al‐deficient (Al62Cu23Cr15) and Al‐rich (Al68Cu17Cr15) quasicrystalline alloys
Authors: Khare V. , Tiwari R. S. , Srivastava O. N. 
Published: January 2007

AbstractIn the present work investigations on the effect of stoichiometric variations on the Occurrence and stabilization of quasicrystalline (qc) and related phases have been carried out. Based on the explorations of several Al‐deficient and Al‐rich versions of the ideal nominal composition i.e. Al65Cu20Cr15, it has been found that the alloy compositions corresponding to Al62Cu23Cr15 (Al‐deficient) and Al68Cu17Cr15 (Al‐rich) exhibit several structural subtleties. The Al‐deficient alloy, has been found to exhibit crystalline bcc and fcc phases with a = 8.90 Å and a = 17.98 Å respectively. In addition to these phases, a new crystalline bcc variant (a = 15.42 Å) originating from the bcc (a = 8.90 Å) phase has been found. Also a curious superstructure of the fcc (a = 17.98 Å) has been observed. The Al‐rich alloy typified by Al68Cu17Cr15, on the other hand, does not exhibit any structural variants, instead it shows nearly pure i‐phase.
Crystal Structure Study of Co(II) Complexes with 2,2′‐(1,4‐Ethylenedioxyl) Dibenzoic Acid‐[Co · L · (H2O)3]n · nH2O· 0.2 nH2O
Authors: Yang Guang , Wang Lei , Ji Liang‐Nian , Koh Lip Lin 
Published: January 2007

AbstractThe structure ofS the title complex [Co. L. (H2O)3]n. nH2O. 0.2 nH2O has been established by single crystal X‐ray diffraction. Crystals of the complex are monoclinic, space group C2/c with cell constants α = 45.29(4), b=10.631(6), c = 8.015(6) Å, β = 90.65(8)°, Z = 8, Dc = 1.489 g. cm−3 The structure was solved and refined to R =0.0478 (wR = 0.0577). In the chain structure, Co(II) ions are hexacoordinated by 0 atoms in an octahedral arrangement. CoO6 octahedra share corners (bridged) through O atoms of water, with each L2‐‐ligand binding two adjacent Co atoms.
Low‐temperature Region of the In–Se System
Authors: Tedenac Prof. J.‐C. , Vassilev Dr. G. P. , Daouchi B. , Rachidi J. , Brun G. 
Published: January 2007

AbstractA study of the low‐temperature region of the In–Se system has been performed by means of isothermal annealing of diffusion couples as well as by X‐ray, microscopic and microprobe analyses. Four binary compounds have been observed – In4Se3, InSe, In6Se7 and In2Se3.Original experimental results about the crystal structure and electrical conductivities of the binary compounds have been compared with available literature data or calculated values.A DSC study of the compound InSe has revealed that it melts peritecticly at about 618 °C.The diffusion controlled transition from one In‐Se compound to another can be achieved without kinetic difficulties, following the phase arrangement from the equilibrium phase diagram. There are indications that small deviations from the exact stoichiometric ratios are possible.
Change of the Normal Rate of Hills Growth on the (001) Face of TGS Single Crystal Under Constant Crystallization Conditions
Authors: Bikov A. Z. , Stoichkov S. D. 
Published: January 2007

AbstractConsiderable change (up to 100% in one of the cases) of the normal growth rate of hills on the (001) face of the TGS crystal at strictly constant supersaturation and temperature is registered experimentally.On the basis of the spatial disposition of the dislocations, which form the source of the steps, a model of a growth centre (called herein non‐parallel centre of growth) is proposed. The model is qualitatively concordant with the experimental data.It is shown that the inconstancy of the normal rate of growth at constant supersaturation and temperature is an immanent characteristic of the non‐parallel centre of growth.
Changes of the Dispersive and Phase Composition of Cerox Type Polishing Material as a Result of Exploitation and Mechanoactivation
Authors: Todorovsky D. , Terziev A. , Minkova N. 
Published: January 2007

AbstractThe changes of the dispersive and phase composition of a Cerox type polishing material as a result of its exploitation and mechanochemical treatment are studied. A slightly expressed destruction of the solid solution CeO2‐Ln2O3 during the exploitation and mechanoactivation in water suspension (in centrifugal ball mill) is found out. The mechanoactivation models very well the changes of the dispersive composition of the polishing powder as a result of its use. A similarity in the behaviour of the wasted and the mechanoactivated materials is observed in the case of a treatment with HNO3+H2O2 mixture as well.
PVT and CVT Growth and Characterization of SnSxSe2‐x (0 ⩽ <x 2) Single Crystals
Authors: Patel D. H. , Patel R. G. , Arora S. K. , Agarwal M. K. 
Published: January 2007

AbstractSingle crystals of solid solutions of tin sulphoselenide have been grown in the same ampoule. Specific conditions for growing single crystals of SnSSe have also been identified. A study of microstructures on the growth surfaces responds to the mechanism of growth of these crystals. The dependence of electrical resistivity, Hall mobility, carrier concentration with the values of the configuration parameter x has been studied.
On the conduction mechanism and thermoelectric phenomena in In6S7 layer crystals
Authors: Gamal G. A. 
Published: January 2007

AbstractIn the present paper, measurements of the electrical conductivity and Hall coefficient on single crystal of In6S7, grown by a new crystal growth technique, were done. The crystal was found to be of n‐type conductivity. The low conductivity sample showed as the most striking feature an exponential increase of the Hall mobility with temperature. This effect was explained by assuming a mixed conduction and different scattering mechanisms for electrons and holes in the same temperature range. Also we have made thermoelectric power measurements to support this assumption. An energy gap of 0.64 eV was found.
Problems with the preparation of anhydrous single crystal sulphates. I. M2+SO4 (M = Fe, Co, Ni)
Authors: Růžička M. 
Published: January 2007

AbstractThe article deals with the problems retarded to preparing the single crystals of anhydrous sulphates of the iron‐metal group. The article provides a comprehensive review on up to date recent knowledge on the chemical and physical properties of these sulphates and, in addition, it describes some methods of preparing their anhydrous form. Also inform about the experiments of single crystal growth. It exhibits the facility of the solution of this problem, that is still under investigation.
In situ Observation Setup for Semiconductor Growth Interface from Solution in a Magnetic Field
Authors: Inatomi Y. , Dold P. , Danilewsky A. N. , Benz K. W. 
Published: January 2007

AbstractA setup for in situ observation was developed which makes possible the optical visualization of a solid‐liquid interface during solution growth of semiconductors in an external magnetic field. This setup consisted of an optimized monoellipsoidal mirror furnace, a near‐infrared optical system, and static or rotating electromagnetic facility. The target crystals were GaP, GaAs and CdTe.
Study of Electrical Conduction Behaviour of the System Sr1‐xLaxSn1‐xCoyO3 (x = y ⩽ 0.5; x ⩽ 0.5, y = 0.00; x = 0.00; y ⩽ 0.05)
Authors: Mandal K. D. , Sastry M. S. , Christopher C. C. , Parkash Om 
Published: January 2007

AbstractSingle phase solid solution forms in the Sr1‐xLaSn1‐xCoyO3 (x = y) system for x⩽0.05 in the samples prepared by solid state ceramic method. A few compositions were prepared in the Sr1‐3x/2LaxSnO3 and SrSn1‐yyCoyO3‐y/2 to understand the role of La3+ and Co3+ in the electrical conduction behaviour of the system. Resistivity increases with incorppration of La3+ ions and decreases with doping of Co3+ ions. These results have been explained in terms of the defect structures of these materials.
Some Physicochemical Studies on Organic Analog of Metal‐Nonmetal Eutectics
Authors: Rai U. S. , Rai R. N. 
Published: January 2007

AbstractPhase diagram, growth behaviour, thermochemistry and microstructure of organic analog of metal‐nonmetal systems, namely, urea‐succinonitrile system and diphenyl‐neopentyl alcohol system, were studied. While phase diagram study shows the formation of simple eutectic in each case, the growth kinetics investigations suggest the applicability of Hillig‐Turnbull equation to these systems. The values of entropy of fusion, enthalpy of mixing, Jackson's roughness parameter, interfacial energy and excess thermodynamic functions were calculated using enthalpy of fusion values determined by the DSC method. The microstructure of eutectics were found to be significantly different from those of the parent components.
Formation of the Perovskite Phase Pb3NiNb2O9
Authors: Balzer B. , Langbein H. 
Published: January 2007

AbstractPb3NiSNb2O9 was synthesized via various methods in order to investigate the mechanisms of perovskite formation. Two relatively simple routes to precursors that give single‐phase perovskite after calcination at 900°C are described: a modified columbite‐method and a synthesis from a freezedried complex salt solution. The results show that the formation of perovskite Pb3NiNb2O9 does not start below 900 °C and that the pyrochlore formation beginning at lower temperatures has be hindered by a thermal shock calcination.
Light Scattering Experiments during Freezing and Melting
Authors: Bilgram J. 
Published: January 2007

AbstractAnomalous light scattering has been observed at the solid‐liquid interfaces of high purity systems during freezing as well as during melting. The model substances used are water, salol, cyclohexane and xenon. From light scattering experiments the existence of a layer of pre‐ordered material at the solid‐liquid interface is deduced. Light is scattered by long range fluctuations in this layer. The thickness of this layer is a few μM. The correlation length of the fluctuations in this layer has been determined to be ξ ≈ 260 nm. Dynamic and static light scattering experiments lead to the same correlation length. Xenon, salol and cyclohexane cover a range of a factor of 15 in viscosity at the melting temperature. Growth velocities have been varied by a factor of about 200. Thermal gradients at the solid‐liquid interface have been varied in a wide range. No dependence of the correlation length on these parameters or on substance has been found in the experiments. The observations do not depend on the crystallographic orientation of the crystal surface nor on the orientation of the crystal surface relative to gravity. The interface‐layer may be compared to the quasiliquid layer which has been found at crystal vapour interfaces at conditions close to the melting point. The existence of a pre‐ordered layer in‐between a crystal and its melt means that the crystal does not grow into the melt but into the pre‐ordered layer.
Structural Perfection of ZnSe Crystals Grown by Travelling Heater Method
Authors: Dohnke I. , Mühlberg M. , Neumann W. 
Published: January 2007

AbstractZnSe crystals have been grown by the travelling heater method (THM) with PbCl2 as solvent. Our investigations have shown that ZnSe crystals could be obtained with high crystalline perfection referred to a full width at the half maximum (FWHM) down to 20 arcsec of double crystal rocking curves measured at chemically polished (100)‐oriented surfaces. Solvent growth techniques like THM should have a remarkable potential for ZnSe bulk growth if the capture of solute as inclusion and precipitation can be avoided.
HVC microlesions do not destabilize the vocal patterns of adult male zebra finches with prior ablation of LMAN
Authors: Thompson John A. , Johnson Frank 
Published: January 2007

AbstractThe songs of adult male zebra finches (Taeniopygia guttata) arise by an integration of activity from two neural pathways that emanate from the telencephalic nucleus HVC (proper name). One pathway descends directly from HVC to the vocal premotor nucleus RA (the robust nucleus of the arcopallium) whereas a second pathway descends from HVC into a basal ganglia circuit (the anterior forebrain pathway, AFP) that also terminates in RA. Although HVC neurons that project directly to RA outnumber those that contribute to the AFP, both populations are distributed throughout HVC. Thus, partial ablation (microlesion) of HVC should damage both pathways in a proportional manner. We report here that bilateral HVC microlesions in adult male zebra finches produce an immediate loss of song stereotypy from which birds recover, in some cases within 3 days. The contribution of the AFP to the onset of song destabilization was tested by ablating the output nucleus of this circuit (LMAN, the lateral magnocellular nucleus of the anterior nidopallium) prior to bilateral HVC microlesions. Song stereotypy was largely unaffected. Together, our findings suggest that adult vocal production involves nonproportional integration of two streams of neural activity with opposing effects on song—HVC's direct projection to RA underlies production of stereotyped song whereas the AFP seems to facilitate vocal variation. However, the rapid recovery of song in birds with HVC microlesions alone suggests the presence of dynamic corrective mechanisms that favor vocal stereotypy. © 2006 Wiley Periodicals, Inc. Develop Neurobiol 67: 205–218, 2007.