bluuebunny/crossref_metadata_2025_split huggingface dataset:
AES Depth Profiling of Nitrogen Implanted Fe(001)
Authors: Zemek Josef , Van Phac Le , Král Jaroslav 
Published: January 2007

AbstractAuger electron spectroscopy (AES) combined with a well controlled ion mill is applied for the study of nitrogen implanted (N+2 ions, 120 keV) into iron single crystals in doses ranging from 8 × 1016 to 5 × 1017 N‐atoms/cm2, also with subsequent heat treatment. The nitrogen depth profiles are Gaussian‐like in shape for doses up to 1.5 × 1017 N‐atoms/cm2. Athigher doses deviations are observed. The nitride bonding state was indicated but a part of the implanted nitrogen appears to be weakly bonded.
On the Formation of the Garnet Phase in Oxidic High‐Temperature Solutions
Authors: Fischer K. , Sinn E. 
Published: January 2007

AbstractThe paper informs on the formation of the garnets Y3Fe5O12, Y3Al5O12 and Gd3Ga5O12 as primary phase in the ternary solvent mixtures PbOPbF2B2O3 and PbOMoO3B2O3. There are correlations with formerly measured oxygen ion concentrations (OIC) in the solvents:
each garnet grows in a special region of the OIC, the phase boundaries are parallel to the lines of constant OIC and
the garnet solubility increases distinctly with decreasing OIC. This emphasizes the important role of the oxygen ions for the garnet formation.
Solubility models are discussed taking into consideration both previous and present results. We conclude that the garnet formation is described best by a model reaction of the type

RE rare earth elements, Y;M Al, Fe, Ga.
Reactor Problems in Modified Chemical Vapour Deposition (II). The Mean Viscosity of Quartz Glass Reactor Tubes
Authors: Kirchhof J. , Funke A. 
Published: January 2007

AbstractA new method is developed for deducing viscosity data from collapse experiments with quartz glass reactor tubes. These data involve informations on temperature differences between outer and inner tube surface which are of great importance to the MCVD procedure. The present investigations supported by some deposition experiments yield the surprising result that a considerable temperature gradient exists also at rather low torch speeds. The reason for this effect is discussed.
Mechanical Behaviour of LiF Single Crystals in Compression and Tension at Temperatures from −196°C to 800°C
Authors: Scvortzova N. P. , Berezhkova G. V. 
Published: January 2007

AbstractThe work hardening characteristics of LiF single crystals in compression and tension has been investigated as a function of temperature. It was shown that in temperature range from 200 °C to 600 °C four stages of hardening were observed and the main part of plastic flow proceeds in stage IV. The parabolic hardening was not observed. The flow stresses and hardening rates in all stages in compression are higher than those in tension. As a temperature increase this difference decreases. The hardening rates, stresses which correspond to the beginning of the linear hardening stages and the duration of those stages decrease as a temperature increase. At temperatures above 600 °C the yield drop occured. Taking into account a good agreement between the temperature dependences of the critical resolved shear stress and τIII the assumption was made that τIII corresponds to resolved shear stress in a secondary glide system.
Electrochemical Deposition of CdTe Layers. Their Structure and Electrical Properties
Authors: Valvoda V. , Toušková J. , Kindl D. 
Published: January 2007

AbstractCdTe layers have been deposited catodically on nickel substrates from an aqueous solution of CdSO4 and TeO2. The degree of erystallinity increases with increasing temperature and decreasing deposition potential. The structure of the layers is cubic with 〈111〉 or 〈110〉 texture which is determined by TeO2 concentration predominantly. Amorphous phase is found in deposits prepared at higher deposition potential or at lower temperatures of bath (60 °C). After annealing at 200 °C the amorphous deposits crystallized and pure tellurium appeared in diffraction spectra. The resistivity of the films was determined by means of I—V characteristics. Films with deposition potentials (−500 to −400) mV vs SCE are p‐type conductivity whereas at lower potentials (down to − 700 mV vs. SCE) the n‐type material is formed.
Temperature Distribution of a Floating Zone in Electron Beam Zone Melting of Molybdenum
Authors: Göbel R. , Jurisch M. , Löser W. , Martuzāne E. , Martuzāns B. 
Published: January 2007

AbstractThe temperature distribution in the molten zone for the electron beam zone melting of molybdenum was calculated on the basis of a heat flow model of the rod. Input parameters were the measured axial electron beam density distribution at the rod surface and the supplied power. The calculated zone shape is compared with experiments. Conclusions are drawn on the magnitude of the dimensionless hydrodynamic parameters of the floating zone in dependence on the experimental conditions.
Lattice Thermal Expansion in CuGaT2 and CuInTe2 Compounds over the Temperature Range 80 to 650 K from X‐ray Diffracion Data
Authors: Bodnar I. V. , Orlova N. S. 
Published: January 2007

AbstractThe lattice parameters a and c as well as the thermal expansion coefficients α⟂ and α∥ in the two principal direction for CuGaTe2 and CuInTe 2 chalcopyrite‐type compounds have been determined as a function of temperature in the range from 80 to 650 K by the X‐ray diffraction method. It is found for both the compounds the coefficient of expansion along the α axis (α⟂) is larger than that along the c axis (α∥) over the whole investigated tem‐perature range. When comparing the results for a series of the CuBIIIC compounds (BGa, In; CS, Se, Te) it is shown that the thermal expansion anisotropy increases strongly when the Ga atom replaces the In atom while it changes a little when the Te atom replaces the Se atom or the S atom.
Dielectric Relaxation on the Smectic B Phase in a Binary Mixture
Authors: Kresse H. , Stettin H. , Tennstedt E. 
Published: January 2007

AbstractDielectric relaxation measurements in the frequency range from 10 Hz to 100 kHz in the SA, SB, and SF phase of the binary system 4‐n‐pentyloxybenzylideneamino‐4′cyanobiphenyl(1)/4‐n‐octyloxyphenyl trans‐4‐n‐octylcyclohexanecarboxylate have been carried out. The systematical change of the relaxation frequency FR of I for the reorientation of the molecules around their short axes has been studied in the SB phase for different concentrations. A maximum of FR at the mole fraction 0.5 has been detected which could indicate a decrease of the three dimensional correlation in SB. The increase in FRis connected with a decrease of the activation energy of the respective relaxation process.
Interface Kinetical Limitations in Closed‐Tube Chemical Vapour Transport (I)
Authors: Paorici C. , Pessina V. , Zecchina L. 
Published: January 2007

AbstractA semiempirical method is proposed, by which the role of kinetical constraints to the growth in closed tube chemical vapour transport can be evidenced.The method is based on the evaluation of the ratio (Φ) between the quantity D which is related to the semiempirically‐determined average diffusivity of the gaseous species during the growth process, and the quantity D, which is related to the maximum average diffusivity of the gaseous species as is predicted, through the choice of a suitable diffusional model, by the equilibrium thermodynamics and diffusion properties of the vapour phase.
Bond Ionicities and Structural Trends in Some LiBIIIC Compounds
Authors: Neumann H. 
Published: January 2007

AbstractThe individual and average bond ionicities of LiAlO2, LiGaO2, LiInS2, LiInSe2 and LiInTe2 are evaluated from spectroscopic data. It is found that in these compounds the LiCVI bond is essentially ionic in nature. It is shown that the structural properties of the compounds can be understood in terms of the average bond parameters.
The Coprecipitation of Zinc Aluminium Hydroxide Powders from Aqueous Solution with Sodium Hydroxide: Precipitate Compositions and Coprecipitation Mechanisms
Authors: Packter A. , Derry A. 
Published: January 2007

AbstractZine aluminium hydroxides were coprecipitated from different mixed metal cation solutions, at CM tot = 0.1 M and at Zn/Al2 ratios from 1 to 4, with sodium hydroxide solution. The coprecipitations were monitored by potentiometrie (pH) titration and the final coprecipitate compositions were examined by chemical analysis, infra‐red spectrophotometry and thermal analysis.Generally, microcrystalline aluminium hydroxide was first precipitated at pH about 4; this then partially redissolved on further addition of sodium hydroxide (to form hydroxoaluminate anion) and zinc aluminium hydroxide coprecipitates were formed continuously at pHs from 5.5–6 to above 9. Their compositions were similar to the magnesium hydroxoaluminate coprecipitated from magnesium aluminium solutions.At Zn/Al2 ratio = 1, the main phase was probably Zn(H2O)n [Al(OH)4]2; at Zn/Al2 ratio = 2, the main phase was probably Zn2(H2O)n [Al2(OH)10], whereas at Zn/Al2 ratio = 4, the main phase was probably Zn(H2O)n(OH)4[Al2(OH)10].
On the Size Distribution of Guinier‐Preston Zones Grown in an Al‐4.5 at.% Zn Alloy at Room Temperature
Authors: Hübner G. , Löffler H. 
Published: January 2007

AbstractThe size distribution SD of the Guinier‐Preston (GP) zones grown in an Al‐4.5 at.% Zn alloy were determined by analysis of the intensities of the small‐angle X‐ray scattering (SAXS) curves. Four different methods frequently used in the literature were applied and the obtained results were compared. In addition the SD's obtained by the SAXS methods were compared with that found by high‐resolution electron microscopic investigations. – From these comparisons conclusions were drawn.
The Coprecipitation of Magnesium Titanyl Hydroxide Powders from Aqueous Solution: Precipitate Compositions and Coprecipitation and Ageing Mechanisms
Authors: Packter A. , Derry A. 
Published: January 2007

AbstractSeries of magnesium titanyl hydroxides were coprecipitated at ambient temperature, from different mixed metal cation solutions at CM tot = 0.1 M and Mg/TiO ratios from 2 to 1/2), with sodium hydroxide solution. The relevant single precipitations and the coprecipitations were monitored by potentiometric pH titration and the final coprecipitate compositions were examined by chemical analysis, infra‐red spectrophotometry and thermal analysis.The main coprecipitates were «intramicellar mixtures» of microcrystalline titanyl hydroxide with excess magnesium hydroxide or of magnesium hydroxide with excess titanyl hydroxide. The coprecipitates aged in alkaline magnesium hydroxide suspension were mixtures of titanyl hydroxide, magnesium hydroxide and from fifty to ninety percent (relative to the original/magnesium content) of magnesium hydroxotitanate hydrates Mg[TiO(OH)4] · h H2O, Mg[TiO2(OH)2] · h H2O and Mg[Ti2O2(OH)6] · h H2O.
About the Fluorine Chemistry in MCVD: The Influence of Fluorine Doping on SiO2 Deposition
Authors: Kirchhof Johannes , Kleinert Peter , Unger Sonja , Funke A. 
Published: January 2007

AbstractIn the fabrication of quartz glass fibers for optical communication, fluorine doping gets increasing importance. In contrast to other dopants, fluorine influences the deposition of SiO2 in Modified Chemical Vapour Deposition. An equation is derived from considerations of equilibrium chemistry which yields the deposition efficiency of SiO2 as function of fluorine doping. It is compared with experimental results.
Thermal Microscopy and DSC Studies of 4‐[4‐n‐pentyloxybenzylideneamino] Azobenzene
Authors: Rao K. R. K. , Rao J. V. , Venkatacharyulu P. , Rao S. V. Chiranjeevi , Ballah V. 
Published: January 2007

AbstractPhase transition studies of the liquid crystal, 4‐[4‐n‐pentyloxybenzylidene–amino]–azobenzene (PBAAB) have been investigated by thermal microscopy and Differential Scanning Calorimetry (DSC) studies. From these studies it is confirmed that the compound, PBAAB exhibits nematic, smectic A and smectic B phases. The textures exhibited by different phases are presented. The enthalpies and entropies at various phase transitions are also reported.
Thermal Expansion of SrF2 at Elevated Temperatures
Authors: Kommichau G. , Neumann H. , Schmitz W. , Schumann B. 
Published: January 2007

AbstractThe X‐ray method was used to determine the linear thermal expansion coefficient of SrF2 in the temperature range from 301 to 1173 K. A comparison of the thermal expansion coefficients of CaF2, SrF2 and BaF2 at T > 300 K shows that the degree of lattice an–harmonicity in the alkaline earth fluorides decreases with increasing mass of the alkaline earth atom. The results for the thermal expansion of SrF2 are used to discuss the temperature dependence of the lattice mismatch in the SrF2/InP film–substrate system.
Thermoanalytical and morphologic study of gel‐grown silver (I) chromate single crystals
Authors: Büchele W. , Lentz A. 
Published: January 2007

AbstractRhombic single crystals of silver (I) chromate were grown in silica gels. They were of tabular shape with a size of a = 0.3, b = 30 and c = 3 mm. The morphology of the crystals was interpreted by a detailed discussion of the structure. Silver (I) chromate consists of (100) layers connected along the a‐axis by silver atoms in octahedral coordination. The crystals were characterized by their powder diffraction data. Differential thermal analysis studies were made by use of single crystals. The enthalpy of the phase transformation taking place at 485.2 °C is found to be ΔHtr = 8.8 kJ/mol.
Microcracks in fatigued FCC polycrystals by interaction between persistent slip bands and grain boundaries
Authors: Dörr G. , Blochwitz C. 
Published: January 2007

AbstractPersistent slip bands (PSB) are zones of high plastic strain localization in fatigued fee metals. They cannot propagate across the grain boundaries of polycrystalline specimens. Consequently, a local stress field should exist near the end of the PSB, “inducing” new PSBs in the neighbouring grain or initiating cracks within the grain boundary. This interaction between PSBs and grain boundaries will be discussed in the present paper. The observed effects may be divided into few characteristic groups, the occurrence of which depends on the geometrical relations between PSB, grain boundary and specimen axis.
Material consideration for the growth of scintillation grade NaI(Tl) crystals
Authors: Sabharwal S. C. , Ghosh B. 
Published: January 2007

AbstractThe starting material for any crystal growth contains a number of impurities. The level of an impurity affecting a particular property of the crystal varies from one impurity to another. We report here the effect of some select impurities usually present in NaI material on its growth and scintillation response.
On the initial stages of skeletal crystal growth
Authors: Nanev Chr. N. 
Published: January 2007

AbstractThe transition from isometric into skeletal form of a crystal growing under diffusion control is explained as a result of the transition from a global compensation of the super‐saturation nonhomogeneity, i.e. in the framework of the whole crystal face, to a spatially limited one. The said compensation is now possible only in the region of the macroscopically flat margin surrounding the gross morphological defect (in the form of a depression) which is the immediate result of the uneven, and unsufficient matter supply.
Precipitation studies in a foam column: Potash alum from aqueous solution using 2‐propanol
Authors: Halasz S. , Mullin J. W. 
Published: January 2007

AbstractA pneumatically‐mixed foam column is described for the precipitation of potash alum from aqueous solution using 2‐propanol as the water‐miscible salting‐out agent. Controlled precipitation is achieved by first evaporating the alcohol into the foam‐producing air stream. Guidelines are given for some optimum modes of operation.
Application of neutron diffraction methods to texture studies on natural rock salt
Authors: Ertel A. , Betzl M. , Paufler P. , Voitus W. 
Published: January 2007

AbstractThe changes for successful texture studies using neutron diffraction on coarse‐grained natural rock salt are tested. The advantages of neutron diffraction for texture investigations of geological materials have been demonstrated and the process of specimen preparation is shortly described. For texture studies conventional angle dispersive neutron diffraction has been applied. Complete pole figures were measured using the spherical sample method and a combination of transmission and reflection geometry in diffraction experiments for rock salt slabs. Due to the small number of crystallites within the irradiated specimen volume composite pole figures had to be scanned using two or three single experiments. The initial material for our studies is natural rock salt from Zielitz mine (near Magdeburg, GDR). Pole figures were measured for the (200), (220), and (222) reflections of NaCl. The crystallographic texture of all samples investigated is weak. In general (100) fibre textures were found.
Contrast formation in plane wave topographs of quartz crystals with induced growth striations
Authors: Alter U. , Cuamba B. , Härtwig J. 
Published: January 2007

AbstractA qualitative and quantitative study of the contrast formation in X‐ray plane wave topographs of quartz plates with induced growth striations is presented. Contrast distributions are calculated by means of a simple local application of the dynamical theory of the X‐ray diffraction from the perfect crystal and using a mathematical model of the lattice deformation according to the isotropic theory of elasticity. A good agreement between calculations and experimental results can be stated.
Inclusions in flux‐grown crystals of corundum
Authors: Watanabe K. 
Published: January 2007

AbstractSingle crystals of corundum were grown by the seeded techniques, such as stationary, seed‐rotation, and top‐seeded, from molten Na‐ or Li‐cryolite (Na3AlF6 or Li3AlF6) flux. Inclusions, which are flux inclusion, negative crystal, and cavity, included in the crystals are examined under an optical microscope, and the formation mechanism and the shape of them depending on the differences of growth technique and growth condition are briefly described.
Crystal and molecular structure of 5,6‐diphenyl‐2‐(α‐formyl‐benzyliden)‐2H‐thiopyranes
Authors: Sieler J. , Richter R. , Pulst M. , Leban I. 
Published: January 2007

AbstractThe crystal and molecular structure of the title compound has been determined by X‐ray diffraction techniques. It crystallizes in the monoclinic space group P21/n with cell parameters a = 6.101(3) Å, b = 14.365(6) Å, c = 21.888(7) Å, β = 90.20(4)°, Z = 4. The structure was solved by direct methods and refined by least‐squares calculations to an R value of 0.074. The molecule exists in solid state in the Z configuration. The very short intramolecular OS distance of 2.654(8) Å can be explained with polar interactions between the O and S atoms.
The crystal and molecular structure of 2,5‐dibromo‐1,4‐phenylenediyl bis(trans‐4‐ethylcyclohexanoate)
Authors: Hartung H. , Baumeister U. , Schröter R. 
Published: January 2007

AbstractThe title compound with the formula C2H5C6H10COO‐C6H2Br2OOCC6H10C2H5 (DPBEC) crystallizes in the monoclinic space group P21/c with a = 15.37(2), b = 5.27(1), c = 15.13(2) Å, β = 92.7(1)° and two molecules per unit cell. The structure was solved using film intensity data by heavy atom method and refined to R = 0.078.The fully stretched DPBEC molecules exhibit exact Ci symmetry. Their packing in the crystal is characterized by a non‐parallel (cross) arrangement of the molecular long axes.
Texture investigations of MnAl magnets by neutron time‐of‐flight diffraction
Authors: Fuentes L. , Feldmann K. , Walther K. , Drechsler L. P. , Doerfel I. , Vlassova E. N. , Matorin V. I. , Betzl M. 
Published: January 2007

AbstractIn the present work the connection between magnetic properties and texture of two samples of the tetragonal MnAl phase is investigated. The specimens have been prepared by different cold deformation methods to get various texture types. For texture analysis neutron time‐of‐flight technique has been applied. Some aspects of the mathematical treatment of experimental data has been discussed. The main texture components in the inverse pole figures are inclined with respect to the direction of easy magnetization. Therefore, improved magnetic properties of the material can be expected using more optimal preparation techniques.
Microhardness studies of ammonium hydrogen tartrate single crystals
Authors: Desai C. C. 
Published: January 2007

AbstractSingle crystals of ammonium hydrogen tartrate AHT NH4HC4H4O6 have been grown employing the controlled reaction between NH4Cl and (CHOHCOOH)2 by slow diffusion process in silica gels. The variation in the microhardness of AHT crystals has been determined using Vicker's microhardness indentor. The effects of annealing and quenching on the mechanical properties of these crystals have been studied. It is observed that: (i) irrespective of the relative orientation of the indentor and the crystal, the median vents initiated at the sharp indentation edges, (ii) the microhardness of the crystals depends on the applied load, (iii) the microhardness of the crystal is independent on the duration of loading, and (iv) maximum plasticity is observed in quenched crystals. The implications of this behaviour are discussed.
Morphology of sic epitaxial layers grown by temperature gradient zone melting (I). Dependence of the crystallization boundary smoothness on the epitaxial layers growth conditions
Authors: Peev N. S. , Tairov Yu. M. , Smirnova N. A. , Kalnin A. A. 
Published: January 2007

AbstractThe dependence of the smoothness of the crystallization boundary on the temperature gradient zone melting conditions is investigated. The observed depth of the crystallization boundary is compared with the depth, calculated by the method proposed by D. E. TEMKIN.
A new equation for the temperature dependence of density of saturated aqueous solutions of electrolytes
Authors: Sangwal K. 
Published: January 2007

AbstractA new empirical three‐parameter equation d = d0 exp[β′(T – T0)2] (where β′, d0, and T0 are constants for a salt) has been proposed to describe the dependence of density d (g/ml3) of saturated aqueous solutions of electrolytes on temperature T (K) in the whole range of temperature in which solubility increases or decreases with an increase in temperature.
Crystal structure determination of 2‐acetylamino‐4‐benzoyl‐5,5‐dimethyl‐4,5‐dihydro‐1,3,4‐thiadiazolin, C13H15N3O2S
Authors: Kuban R.‐J. , Schulz B. 
Published: January 2007

AbstractThiosemicarbazone is receiving increasing interest because of the biological activity of some of its derivatives. Mr = 277.35, space group P212121, Z = 4, a = 9.290(3), b = = 11.512(2), c = 13.286(2) Å, V = 1421 (1) Å3, Dm = 1.29(1) Mg m−3, Dx = 1.296 Mg m−3, λ(MoKα) = 0.71062 Å, μ = 0.230 mm−1, F(000) = 584, T = 296 K, final R = 0.028 for 1255 reflections. All hydrogen atoms were located. The structure determed by X‐ray analysis confirms the chemical results. The structure analysis of the title compound is described and its molecular and crystal structure discussed.
Melting temperatures of NaClO3‐NaBrO3 mixed crystals
Authors: Subhadra K. G. , Hussain K. A. 
Published: January 2007

AbstractThe melting points of mixed crystals of sodium chlorate and sodium bromate have been determined. The variation of melting point with composition is non‐linear with negative deviations from linearity. This negative deviation from linearity is attributed to a possible increase in the vacancy concentration in mixed crystals as compared to the pure end crystals.
Grain size distribution in the Kolmogorov model for nucleation and growth: Heterogeneous versus homogeneous nucleation
Authors: Lorenz B. 
Published: January 2007

AbstractA theory of grain size distribution in nucleation and growth reactions described by the KOLMOGOROV model is developed. The distribution of agglomerates of growing and impinging nuclei is explicitely calculated for the two cases of heterogeneous and homogeneous nucleation. The results are compared and discussed with respect to the investigation of the nucleation mechanism in crystallization processes.