bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of the bending radius and diffraction profile parameters for X‐Ray Analyzer Crystals with X‐ray parallel beam
Authors: Kogan M. T. , Shechtman V. M. 
Published: January 2007

AbstractA technique is proposed based upon angular scanning of a bent crystal shifted from the rotation axis. The axis‐to‐crystal distance providing the maximum reflecting efficiency is used to determine the bending radius of reflecting planes, and the diffraction profile can be obtained using an efficiency variation with a crystal shift tangential to Rowland circle at front focus. A rocking curve plotted — a “topogram” of the crystal surface is used to measure its reflecting area and a regularity of bending.The technique is suitable for various types of analyzers in both the reflecting and transmitting arrangements. Instrumental conditions are defined and some experimental examples are given.
The effect of impurity complexes on the shape of PbTe and Bi2Te3 crystals
Authors: Smorodina T. A. , Sheftal N. N. , Tsuranov A. P. 
Published: January 2007

AbstractThe causes of strong dependences of the external shapes of lead and bismuth telluride crystals grown under conditions close to equilibrium on the deviation from stoichiometric composition have been investigated. Auger‐analysis of lead telluride and its solid solutions indicates the change in the character of bonding in the subsurface layers connected with appearence of smooth faces not belonging to the equilibrium shapes of pure substances. The surface phase existance has been explained on basis of statistical thermodynamics within the framework of the Guttman model and due to the formation of „the crystalline”︁ impurity complexes in a layer medium in contact with the growing crystal surface. Particles attachment to the crystal under these conditions proceeds in two stages, which facilitates crystal growth.
A position study on the effect of C, Cu, Ni and Sb on the defect annealing in cold‐rolled iron
Authors: Dlubek G. , Brümmer O. , Mikhalenkov V. S. , Yli‐Kauppila J. , Vehanen A. , Hautojärvi P. 
Published: January 2007

AbstractPositron lifetime and angular correlation measurements are used to study the formation of defects and their annealing behaviour in cold‐rolled pure Fe and dilute Fe alloys with C, Cu, Ni, and Sb. The results show that positrons are trapped by dislocations and vacancy clusters. The effect of foreign atoms on the cluster formation and the annealing properties are discussed.
The crystal and molecular structure of the Nematogenic Compound 5,8‐Dihydro‐5,8‐methano‐1,4‐naphthalenediyl Bis(4‐ethoxybenzoate)
Authors: Baumeister U. , Hartung H. , Jaskólski M. 
Published: January 2007

AbstractSingle crystals of the title compound with the formula (C2H5OC6H4COO)2C11H8have been investigated by X‐ray analysis. The compound crystallizes in the monoclinic space group P21/n witha= 8.555(1),b= 15.280(2),c= 19.093(3) Å, β = 94.17(1)0,V= 2489.2(5) Å3, andZ= 4. The structure was solved by direct methods and refined to a finalRvalue of 0.062The molecule adopts an almost stretched form. The norbornene skeleton within the central part of the molecule is disordered and occurs in two different conformations. The molecular packing is characterized by different lattice regions: the molecules in one region are parallel but their long axes are inclined by 49.5° to the molecules of the other region.
The Electrohydrodynamical Transient instability region in Smectic C liquid crystals
Authors: Petrov M. , Simova P. 
Published: January 2007

AbstractThe hydrodynamical instability transient region between conducting („initial”︁ domains) and dielectric („fundamental”︁ domains) regimes in smectic C is investigated. Two‐dimensional domain structure and two‐dimensional coherent light diffraction is observed in the transient region. A comparison with electrohydrodynamical instability transient region in nematics is presented.
Electrical conduction in organic polyiodide chain complexes
Authors: Oza Ajay 
Published: January 2007

AbstractThe electrical conductivities of three organic polyiodide chain complexes, α‐cyclodextrin‐KI‐I2 · 4 H2O amylose‐iodine and (coumarin)4‐KI‐I2 are observed to be decreased at high pressure upto 80 Kilobars along the direction of iodine chains. The lowering of conductivities at high pressures and the Arrhenius‐type temperature dependences are explained with disordered semiconductor model. The disordered environement of polyiodide chain which lead to weak or strong localization of the charge carriers is discussed. The charge carriers move by thermally‐activated hopping with the energies away from the Fermi energy level.
Glow curves and the emission of BaFCl:Eu2+
Authors: Somaiah K. , Hari Babu V. 
Published: January 2007

AbstractThermoluminescence and the emission of γ‐irradiated BaFCl:Eu2+ has been studied. A well defined glow peak at 400 K and a shoulder at 480 K are obtained in addition to those obtained as in undoped BaFCl. Thermoluminescence emission has shown a band at about 390 ∼ 400 nm. Additional glow peaks have been attributed to the luminescence centers as caused by europium impurity.
Deformation modes in plasticity and fracture
Authors: Indenbom V. L. , Orlov A. N. 
Published: January 2007

AbstractThe character of collective motion of the point defects and dislocations of various types determines the mode of plastic deformation and of fracture as its final stage. The concepts of the translational and rotational modes appeared at an early stage in the study of the mechanisms of plastic deformation in crystals and have undergone substantial evolution in connection with the development of methods for the direct observation of lattice defects. As a rule, different modes, e.g. diffusion and dislocation plasticity, translations and rotations, slip and twinning, plasticity and fracture, etc. are interrelated. The conditions for the loss of stability in plastic deformation and fracture are discussed. The rotational modes of plastic deformation are shown to be a consequence of the translational ones. The disclination modes are demonstrated to result from a simplified description of the dislocation kinetics.
Effect of impurities on dynamic dragging of dislocations
Authors: Natsik V. D. , Chishko K. A. 
Published: January 2007

AbstractThe rearrangement of the force of dynamic dragging of a dislocation due to its elastic interactio in with impurity atoms is analysed. The collisions of a moving dislocation with impurities excite additional vibrations of a dislocation line. Such vibrations lead to the appearance of extra parts to dissipative function and effective friction force of a dislocation which depend on location and concentration of impurities. This effect is one of the reasons of the influence of impurities observed in the experiments on the dynamic branch of the moving dislocation curve.
Formation of dislocation structure in shaped single crystals during their growth from the melt by Stepanov's Method
Authors: Antonov P. I. , Bakholdin S. I. , Krymov V. M. , Nikanorov S. P. 
Published: January 2007

AbstractThe paper is concerned with the formation of a dislocation structure due the thermal stresses in shaped single crystals with different degree of anisotropy grown by Stepanov's method. The calculation of root‐mean‐square tangential stresses allows to determine the regions in which the plastic deformation may occur. Analysis of thermal stresses in separate slip systems permits to explaine the slipe band distribution in shaped single crystals.
LPE growth of p(n)InAs1‐ySby‐n(p)GaSb(AlxGa1‐xSb) Heterostructures
Authors: Pramatarova L. D. 
Published: January 2007

AbstractThis paper presents the results of LPE–growth of p(n)InAs1‐ySby‐n(p)GaSb(AlxGa1‐xSb) heterostructures. It is shown the optimum technological regimes for growth of heterostructures p(n)InAs1‐ySby‐n(p)GaSb(AlxGa1‐xSb) with a decreased lattice matching of the materials forming the heterojunction.
Some crystallographic trends into the Na1+xZr2SixP3‐xO12 System
Authors: Krajewski A. , Valmori R. , Fiegna A. 
Published: January 2007

AbstractThis paper gives a contribution to the crystallographic characterization of the Na1+xZr2SixP3‐xO12 system, useful e.g. to analyze the right stoichiometric composition of a synthesized sample concerning this family of compounds, by powders X‐ray diffraction analysis. In the paper relations are in fact displayed to exist among dhkl, unit cell parameters and the stoichiometric parameter x. Such relations show to be linear for dhkl and a0, while the relation trend involving c0 let one think the system is isostructural in the atomic arrangement for the ranges x < 2 and x<2, respectively, to the end terms with x=0 and x=3.
Effect of Flux on thermoluminescence in Flux‐grown BaFCl crystals
Authors: Somaiah K. , Hari Babu V. 
Published: January 2007

AbstractBaFCl crystals have been grown using BaF2 and BaCl2 by flux technique. Glow curves, optical absorption, and TL emission spectra of x/r — irradiated crystals are studied. The results have been compared with those BaFCl crystals grown from NaF flux so as to study the effects of flux on these properties. It is found that crystals grown from BaF2 flux are relatively purer. An additional TL glow peak at 460 K, an optical absorption band at 775 nm and TL emission band at 485 nm have been obtained in the presently grown crystals. The additional glow peak, optical absorption band have been attributed to F(¯F) aggregate centers, whereas the 485 nm TL emission band to impurity centers.
The effect of iron on the precipitation in an Al‐Mg‐Si alloy
Authors: Schmidt U. , Joachimi M. , Petzold L. , Eichhorn F. 
Published: January 2007

AbstractThe effect of iron on the precipitation of a technical Al‐Mg‐Si alloy was studied by macroand microhardness, Y‐modulus and SANS with DKD and was compared with a pure alloy. The iron phases of the technical alloy were preferentially considered by the SANS. In addition the damping by the elastomat of FÖRSTER and the variance of the microhardness were measured. It was found that iron essentially influences the kinetics of the precipitate, particularly the mechanism of nucleation and precipitation sequence.
Effect of the magnetic flux trapping upon the temperature dependence of the flow stress change at the superconducting transition
Authors: Dotsenko V. I. , Pustovalov V. V. , Sirenko V. A. , Fomenko V. S. 
Published: January 2007

AbstractThe effect of the superconducting transition on the flow stress in single and polycrystals of Pb‐In and Pb‐Sn alloys has been studied in the temperature range 1.8 K toTe. Unlike earlier efforts, these experiments involved investigation of the magnetic flux trapping. Two types of temperature dependences of the magnetic flux trapping,B0(T), were revealed. In Pb‐1.9 at.% In and Pb‐6 at.% Sn alloys (subjected to various thermal treatment),B0monotonically rises with lowering temperature. In Pb‐1.8, 3 at.% Sn single crystals the flux trapping arises at high strains (> 50%) and low temperatures (<2.5 K). In this caseB0magnitude depends on the strain rate. The difference in theB0(T) behaviour is associated with dissimilar flux pinnig by pinning centres. The date onB0(T) obtained give an insight into the two types of the Δσ(T) dependences; taking into account of the flux trapping allowed the Δσ values to be corrected, so that as a result, a single ΔσSN(T) curve was obtained for all the alloys and structures studied.
Coherent spinodal decomposition of equimolar mixed crystals of NaCl‐KCl
Authors: Andreev G. A. , Buritskova L. G. 
Published: January 2007

AbstractBulk density changes have been observed in equimolar mixed crystals of NaCl‐KCl by flotation technique at RT. The results are accounted for on the basis of the theory of coherent spinodal transformation. The interdiffusion coefficient has been estimated from the kinetics of the transformation in the crystals.
Plastic deformation and fracture in LiF Bicrystals with asymmetric tilt boundary
Authors: Smirnov B. I. , Snezhkova T. N. , Volkova O. L. 
Published: January 2007

AbstractThe peculiarities of plastic deformation and fracture in isoaxial LiF bicrystals with misorientation angle α = 10° and tilt boundary of various asymmetry were experimentally studied by the single slip method. It was found that a number of effects at the boundary, attacked by mixed dislocations, is possible: retardation of dislocations near the boundary and pile‐ups formation, dislocation multiplication, accumulation of grain boundary dislocations with differential Burgers vector. Predominance of each or that effect in the process of crack initiation at the definite misorientation angle depends on the mutual orientation of slip planes in the neighbouring grains and on the edge and screw component part in the dislocations, attacking the boundary. The main role, apparently, belongs to dislocation pile‐ups. Cracks are always nucleated in the boundary, but in the case of strong asymmetry they stretch along cubic planes.
Investigations on mechanical properties and chemical composition of thermally treated TiCx coatings on steel (CVD technique)
Authors: Fischer W. , Wetzig K. , Seidler M. 
Published: January 2007

AbstractThe described technology allows the production of dense TiCx coatings onto steel at standard pressure. The residual stress in the coatings is a compressive one with a level of some GPa. It is lowered with an increase of the coating thickness and/or a substrate hardening. Both the residual stress level and the constitution of the contact region substrate/coating mainly influence the mechanical behaviour under external load. An occasional formation of cementite islands on the substrate surface in the initial stage of the deposition process reduces the adhesion of the coating. The coating failure of substratehardened samples has not to occur as a necessity at the contact region, but is possible also by breaking out inside the coating. Besides, the existence of voids along the contact region was observed in this case.
Apparent threshold characteristics of pretilted nematic layers
Authors: Hauck G. , Koswig H. D. 
Published: January 2007

AbstractThe influence of pretilt angles on the voltage dependence of the transmission of nematic liquid crystal cells has been investigated. A conception of an apparent threshold voltage and voltages of other selected deformation states characterized by a parameter A has been introduced. The dependence of the apparent threshold voltage on the pretilt angle is shown in experimental curves. An analytical expression of this dependence could be derived starting from a mean deformation angle.
A contribution to the kinetics of crystallisation of GaP by SSD process
Authors: Weinert B. , Buhrig E. , Hein K. 
Published: January 2007

AbstractThe influence of some important factors which appear during the synthesis of GaP by the SSD‐Process have been comprehended, and their mathematical relationships determined. The model for the growth of crystallisation is valid only for some definite and selected moments. For long‐time experiments the computation of the speed of crystallisation should be carried out step‐by‐step.
Photoelectron spectroscopic studies of anodic potentiostatic oxidation on various platinum surfaces
Authors: Wagner N. , Brümmer O. 
Published: January 2007

AbstractUsing XPS method it is shown that the anodic charge transfer supported oxidation of platinum single crystal electrodes in aqueous 0.1 M HClO4 solution is influenced by the atomic surface arrangements. The best electrode stability is received for the (111) surface with the largest atomic density in the case reported here.
The precipitation of magnesium hydroxoaluminate hydrate powders from sodium hydroxoaluminate solutions: Precipitate phases and precipitation mechanisms
Authors: Packter A. , Slaughter R. A. 
Published: January 2007

AbstractMagnesium hydroxoaluminate hydrates were precipitated from different sodium hydroxoaluminate and hydroxoaluminate‐hydroxide solutions at ambient temperature, at CAl = 0.1 M, OH/Al ratios = 4–9 and XS OH/Al ratios = 1–6. The precipitations were monitored by potentiometric (pH) measurements while the final precipitate compositions were examined by chemical analysis, infra‐red spectrophotometry and thermal analysis.At solution OH/Al ratio = 4, the main precipitate phase at 20°C was Mg(H2O)n[Al(OH)4]2 admixed with some Al(OH)3; at solution OH/Al ratio = 5, the main phase was Mg2(H2O)4[Al2(OH)10]; at solution OH/Al ratio = 7, the main phase was Mg4(H2O)n(OH)4[Al2(OH)10] while at solution OH/Al ratio = 9, the main phase was Mg6(H2O)n(OH)8[Al2(OH)10] admixed with some Mg(OH)2.These hydrates were dehydrated at 60–100°C probably to the compounds Mg2[Al2O3(OH)4], Mg4(OH)4[Al2O3(OH)4] and Mg6(OH)8[Al2O3(OH)4], respectively.
The investigation of P‐ and As diffusion in liquid Gallium
Authors: Gorokhov V. A. , Dedegkaev T. T. , Ilyin Yu. L. , Moshnikov V. A. , Petrov A. S. , Sosov Yu. M. , Yaskov D. A. 
Published: January 2007

AbstractThe results on the As‐ and P‐diffusion in gallium melt are discussed. The definition method of P‐ and As‐diffusion coefficients in liquid gallium was stated. This method was based on the analysis of concentration profile formed during the diffusion annealing with following tempering. The diffusion coefficients were measured on temperature region 1113 to 1383 K. The expression for temperature dependence of diffusion coefficients was obtained.
Unstable internal friction in Bismuth and Antimony single crystals
Authors: Medrano Atencio E. , Pal‐Val P. P. , Ya. Platkov V. 
Published: January 2007

AbstractIn the temperature range of 6 to 300 K an effect of the high amplitude ultrasound waves on amplitudedependences of decrement and modulus defects in the antimony and bismuth single crystals of different orientation is studied. The character of changes of the decrement and modulus defect amplitude dependences under the influence of the high amplitude ultrasound indicates that dislocation multiplication, obstacle break‐through by dislocation pile‐ups or deformation twinning may be observed in crystals depending on the ultrasound propagation direction and the temperature interval investigated.
Growth and morphology of the CuGaS2, CuAlSe2, CuGaSe2 and CuInS2 ternary compounds
Authors: Bodnar I. V. , Bodnar I. T. , Vaipolin A. A. 
Published: January 2007

AbstractMonocrystals of the ternary compounds CuGaS2, CuAlSe2, CuGaSe2, and CuInS2 were grown from their elements by transport reactions; their cell parameters and melting temperature were determined. The character of the phase transition in these compounds was found out and also the boundary conditions of growing the monocrystals as well as their dislocation structure (by etching).
The morphology of hydrothermally grown epistilbite
Authors: Ghobarkar H. 
Published: January 2007

AbstractEpistilbite crystals were grown on the surface of an artifical glass by hydrothermal treatment at 1 kb in the range of 250° to 400°C. Laminar twinned crystals were observed at low temperatures, with increasing temperature twinning decreases and the thickness with respect to [010] increases.
Configuration of grain boundaries
Authors: Herrmann R. , An Nguyen , Worm G. 
Published: January 2007

AbstractIn the present paper a model of the configuration of grain boundaries from a general point of view in the framework of the CSL concept has been developed. Rotations and rotations with translations were taken under consideration. The main result is the determination of the coincidence conditions for symmetrical and asymmetrical grain boundary facets between two and three grains. The facet angles of grain boundaries in any crystal surface are determined.
Influence of impurities, irradiation and temperature on the mechanical and electrical properties of LiF crystals
Authors: Urusovskaya A. A. , Knab G. G. , Regel V. R. , Alekseeva L. I. , Shchepina L. I. 
Published: January 2007

AbstractOn the basis of study of the temperature dependence of mechanical and electrical properties of LiF crystals with different impurities an evident interaction between radiation defects and impurities is revealed. As a result of trapping of radiation defects (F‐ and H‐aggregate colour centres) by impurity centres the reconstruction of impurity centres takes place, causing a change of mechanical and electrical properties.
The study of the influence of γ‐irradiation on LiF crystals by optical, electrical and mechanical characteristics
Authors: Shchepina L. I. , Alekseeva L. I. , Lobanov B. D. , Shuraleva E. I. , Parfianovich I. A. , Knab G. G. , Urusovskaya A. A. , Regel V. R. 
Published: January 2007

AbstractThe influence of the dose of γ‐irradiation on some physical properties (storage of colour centres, ionic conductivity, microhardness) in LiF crystals differing in oxygen content is studied. It is found out that optical, electrical and mechanical characteristics change nonmonotonously with an increase in dose of γ‐irradiation in the range from 104 to 107 J per kg. Maxima and minima are revealed on all the three dependencies, indicating a periodie construction and redistribution of radiation defects during the change of the absorbed dose. Oxygen impurity enhanced the colouring of LiF crystals, significantly reduced the conductivity, caused mechanical softening and intensified the secondary radiation processes having qualitatively changed the behaviour of electrical and mechanical properties with an increase in irradiation dose.
Synthesis and characterization of ferrierite
Authors: Çulfaz Ali , Yilmaz A. Kürşat 
Published: January 2007

AbstractFerrierite, a medium‐port molecular sieve zeolite, was synthesized as the only crystalline phase from an aqueous gel of composition 1.6 Na2O · 1.6 K2O · Al2O3 · 13.5 SiO2 · 130 H2O · 0.8 CO2 · 2.4 (HCO2)2 at 250 °C in reaction periods ranging from 40 to 95 hours. The crystallization time was reduced with seeding. Ferrierite was a metastable phase in this system and it transformed into tridymite, high sanidine and orthoclase at longer reaction periods. At 200 °C, chabazite was crystallized from the same batch composition at a very slow rate. At temperatures higher than 250 °C and in the absence of carbonates and bicarbonates in the batch mixture, tridymite, high sanidine and orthoclase crystallized directly without the formation of ferrierite. The synthetic ferrierite sorbs benzene, toluene and cyclohexane and behaves as a medium port molecular sieve. The sorption capacity of ferrierite was improved by acid treatments with no deterioration of the crystal structure.
Solvent effect on the polytype structure of CdI2 crystals
Authors: Gierlotka S. , Pałosz B. 
Published: January 2007

AbstractSingle crystal platelets of cadmium iodide have been grown from alcohols: n‐propyl, isobutyl and isoamyl and from their aqueous solutions. The structures of 880 crystals has been identified and the effect of solvent on the polytype structure of CdI2 has been discussed regarding: the stability of the basic structures 2H and 4H, the structure of complex polytypes, the effect of the solvent on the structure of faults, the period of polytypes. Some relations indicating the role of the solvent in the formation of polytype structure of CdI2 have been found.
Preparation and electrical conductivity of Pb2Ru2O6.5 crystals
Authors: Řehák B. , Frumar M. , Koudelka L. 
Published: January 2007

AbstractSingle crystals of Pb2Ru2O6.5 have been grown by flux method from a mixture of lead oxides. The electrical conductivity of the crystals is of a metallic type, major current carriers being holes.