bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetics of dissolution of potassium alum crystals in a flow cell in the presence of Fe++ cations
Authors: Karpiński Piotr H. , Larson Maurice A. 
Published: January 2007

AbstractDissolution rates of the {111} face of potassium alum crystals have been measured in situ in a flow cell. Dependence of the mass dissolution fluxes on the subsaturation and on the presence of Fe++ cations has been studied. No influence of these cations over the concentration range 0–165 ppm on the dissolution kinetics has been observed. In addition, the dissolution process has been found to be of a purely diffusive character.
Dielectric and electrical properties of vacuum‐deposited Didymium oxide thin films
Authors: Kumar J. Siva , Rao U. V. Subba 
Published: January 2007

AbstractDielectric and electrical properties of sandwich structures of didymium oxide thin films of several thicknesses have been investigated. The variation of capacitance and dielectric dissipation factor (Tan δ) with frequency in these films have been studied. These studies have shown that at room temperature, the capacitance increases with decrease of frequency and the variation is more pronounced at low frequencies. With increase of frequency, the dissipation factor decreases. The increase of capacitance with decrease in frequency has been attributed to the space‐charge polarisation and blocking of charge carriers at the electrodes. The effect of thickness on capacitance and Tan δ in these films have been studied. Current‐Voltage characteristics (I—V) of sandwiched Al‐didymium oxide‐Al structures have been studied at room temperature. These characteristics showed that the breakdown voltage increases and the dielectric strength decreases with increase of oxide film thickness. Conductivity (σ) at room temperature have been calculated to understand the mechanism involved in the conduction process. These results indicated that the conduction in these films is due to Schottky barriers. Breakdown patterns obtained in these structures by the application of de voltage applied across the sandwich structures have been observed with the help of Carl‐Zeiss, Jena, optical microscope. The photomicrographs of these breakdown patterns indicate that the type of breakdown in these structures may be single‐hole breakdown and is proceeded by propagating breakdown.
The properties of xPbTiO‐ (0.9 — x) PbZrO‐ 0.1 PbW0.5Cd0.5O3 solutions in the region of coexistence of tetragonal and rhombohedral phases
Authors: Kwapuliński J. , Hańderek J. 
Published: January 2007

AbstractThe changes of the dielectric permittivity η, dielectric loss tg δ, piezoelectric coefficient d33, pyroelectric coefficient p, remanent polarization Pr and reorientation processes of polarization in dependence on percent content of PbTiO3 in the xPbTiO3−(0.9 — x) PbZrO3− 0.1 PbW0.5Cd0.5O3 solid solutions in the phase coexistence region (PCR) wree investigated. It was pointed out that the characteristics of mentioned parameters possess singularities in this region. The values of average Curie temperature obtained from structural, dielectric and pyroelectric measurements were compared. Presented results let us connect dielectric properties of studied solid solutions with their structure.
Synthesis, crystal growth and characterization of Tl3BX4‐compounds (B = V, Nb, Ta; X = S, Se)
Authors: Wacker) K. , Buck P. 
Published: January 2007

AbstractSingle crystals of Tl3BX4‐compounds (B = V, Nb, Ta; X = S, Se) were grown by the Bridgman‐Stockbarger technique. The compounds were synthesized from the high‐purity elements. The melting points were determined by differential thermal analysis. Tl3VS4, Tl3TaS4and Tl3TaSe4yielded single crystals up to 10 cm3. The other compounds show single crystalline pieces up to 1 cm3. Infrared photographs and electron microprobe analyses revealed inclusions of TlS in the sulfur compounds, in Tl3VSe4and Tl3NbSe4inclusions of TlSe and in Tl3TaSe4small amounts of Ta.
Growth, X‐ray structure and optical investigations of epitaxial films of solid solutions of lithium niobate‐tantalate
Authors: Madoyan R. S. , Sarkisyan G. N. , Khachaturyan O. A. 
Published: January 2007

AbstractProcesses of the liquid phase epitaxy of films of solid solution of lithium niobate‐tantalate grown from the limited plane‐parallel volume of the liquid phase is considered in the paper. Morphological and structure characterstics of films are investigated. The possibility of the effective use of the obtained structures as active elements of the integrated optics is shown.
Heat and mass transfer in a gas‐transport reactor for multicomponent solid phase deposition
Authors: Barovskii N. V. , Gerzen A. T. , Dobrynin A. V. , Najda G. A. 
Published: January 2007

AbstractGas temperature distribution in an epitaxial horizontal flow reactor was measured by means of a thin thermoprobe and measurement error was calculated. For a turbulent gas flow, the thickness of an equilibrium layer was estimated, the results obtained being coincident with the boundary layer thickness determined from the relationships for gas temperature distribution in the reactor. The distribution pattern of the rates of mass‐transfer processes is discussed with reference to multicomponent solid phase deposition lengthwise the reactor. That the layer of nearly uniform composition can be deposited under turbulent flow conditions only is exemplified by the deposition of solid solutions of aluminium and gallium nitrides.
Raman scattering study of dopant homogeneity in GaP and GaAs single crystals
Authors: Irmer G. , Monecke J. , Siegel W. 
Published: January 2007

AbstractApplication of Raman scattering as a non‐destructive method with high spatial resolution suitable for the determination of charge carrier profiles connected with dopant segregations in polar semiconductors is reported. Single crystals of GaP and GaAs are investigated. The results are in good agreement with electrical measurements.
The order‐disorder transformation at supercooled melt/crystal transition regions of binary melts (II). The steady‐state solution
Authors: Chistyakov Yu. D. , Baikov Yu. A. , Schneider H. G. , Ruth V. 
Published: January 2007

AbstractIn a preceding paper a kinetic master equation has been derived describing the kinetics of atomic exchange processes that occur within the transition region separating a growing binary crystal and its nonsolid surrounding. For simple cubic structures, with the lattice sites being occupied by equal particle numbers of two components (in the case of perfect order corresponding to an NaCl‐type lattice) solutions for the steady‐state conditions have been derived. According to the solutions the long‐range order parameter is related to the atomic interaction energies, the arrival rate of particles at the crystal surface from the melt, and to temperature. A critical supercooling is predicted for the transition from a partly crdered structure to a disordered structure of the crystals growing from the melt. At the critical supercooling the temperature dependence of the crystallization rate reveals a characteristic change.
Surface morphology of iron specimens boronized with BCl3‐H2 mixtures (II) investigation of short‐time gas phase boronized iron surfaces
Authors: Ritzel B. , Bochmann G. , Wagner W. , Marx G. 
Published: January 2007

AbstractSpecimens made of armco iron or pure iron were boronized during a time ≦; 1 minute with 1.1 vol.% BCl3 in H2, and then their surfaces were investigated by scanning electron microscopy and X‐ray diffraction. The boride particles consist of FeB and Fe2B, they crow oriented on the substrate surface, e.g. the Fe2B (110) crystallographic plane is situated parallel to the (111) plane of α‐iron. The polycrystalline substrates are decorated by growing boride particles so that grains, twinning, etc. can be seen. There is a correlation between number per area and size of boride particles in early stages of layer formation and surface morphology in advanced layer growth.
The coprecipitation of magnesium chromium hydroxide powders from aqueous solution: Precipitate compositions and coprecipitation mechanisms
Authors: Packter A. , Panesar K. S. 
Published: January 2007

AbstractMagnesium chromium (III) hydroxides were coprecipitated at ambient temperature from different mixed metal cation solutions — at CMtot = 0.1 M and Mg/Cr2 ratios varying from 1 to 4 — with sodium hydroxide solution. The coprecipitations were monitored by potentiometric (pH) titration and the final precipitate compositions were examined by chemical analysis, i.r. spectrophotometry and thermal analysis. Generally, microcrystalline chromium(III) hydroxide was first precipitated at pH about 5; this material then redissolved on further addition of hydroxyl ion to form hydroxochromate(III) anion and magnesium chromium hydroxide coprecipitates were then formed continuously (at OH/Cr ratios from 4 to 10) at pHs from 9.5–10 to about 11.The coprecipitates from Mg/Cr2 = 1 systems was predominately magnesium hydroxochromate hydrate. The coprecipitates from Mg/Cr2 = 2 to 4 systems were mixture or solid solutions of magnesium hydroxochromate hydrate with increasing amounts of magnesium hydroxide. The ionic equilibria involved in different coprecipitations are discussed.
The determination of liquidus data in the In‐As system
Authors: Knobloch G. , Gottschalch V. 
Published: January 2007

AbstractLiquidus data of the In—As system were determined in the temperature range 450–630 °C using a seed dissolution technique. The analytical estimation of the arsenic content in the melt was carried out by coulometric titration. In the investigated region, the plot of In x(1 — x) versus 1/T shows a weak concave curvature with reference to the 1/T axis.
Deformation state of 49BF‐implanted Si wafers after high‐temperature thermal annealing
Authors: Vassilev I. S. , Petrov I. N. , Botev P. A. , Furmanik Z. , Auleytner J. 
Published: January 2007

AbstractThe bending of 49BF‐implanted Si wafers due to high‐temperature annealing (T = 900 to 1100 °C) is investigated by means of X‐ray topographic techniques. The results are comperatively considered with those for low‐temperature annealing (T ≦ 800 °C) obtained earlier by the authors. It is shown that the most essential differences in low‐ and high‐temperature intervals occur for implantation dose below the amorphization one.
Characterization of single crystal silicon solar cells through illuminated I‐V family curves
Authors: Martell A. , Aguilera S. , Safranova N. , García M. 
Published: January 2007

AbstractIn this paper we analize the illuminated I‐V family curves of the single crystal n/p silicon solar cells obtained in our laboratory. It is demonstrated that through the correction of the higher slope region from the Voc vs ln Isc curve, experimental values of the diffusion current, with great repetibility, are obtained, which are in good agreement with theory. Influence of recombination current on fundamental parameters of solar cells is analized, making use of programable calculator. It is demonstrated that for A ≧ 3 this influence is negligible.
The coprecipitation of calcium aluminium hydroxide (calcium hydroxoaluminate hydrate) powders from aqueous solution with sodium hydroxide: Precipitate compositions and percipitation mechanisms
Authors: Packter A. , Khaw L. F. 
Published: January 2007

AbstractCalcium aluminium hydroxides were coprecipitated from different mixed metal cation solutions — at total CM = 0.1 M and Ca/Al2 ratios from 1 to 4 — with sodium hydroxide solution at ambient temperature. The coprecipitations were monitored by potentiometric (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 redissolved on further addition of sodium hydroxide to form hydroxoaluminate anion and polyanion and calcium aluminium hydroxide coprecipitates were formed continuously at pHs from about 9 to above 12. Their compositions were similar to the calcium hydroxoaluminate hydrates formed by direct precipitation from high pH sodium hydroxoaluminate solutions.At Ca/Al2 ratio = 1, the main phase was probably Ca2(H2O)h[Al2(OH)4]2 with some Al(OH)3;At Ca/Al2 ratio = 2, the main phase was probably Ca2(H2O)h[Al2(OH)10] dehydrating to Ca2[Al2O(OH)8];At Ca/Al2 ratios = 3–4, the main phase was Ca2(H2O)h[Al2(OH)10] with increasing amounts of Ca4(H2O)h(OH)4[Al2(OH)10] and 5–10 percent adsorbed or post‐precipitated Ca(OH)2.
Crystal and molecular structure of 2‐(1‐[alkyl, aryl)‐2‐acylhydrazino]‐4,6‐diaryloxy‐1,3,5‐triazine, C20H19Br2N5O3
Authors: Reck G. , Bannier G. , Just M. , Goldhahn F. 
Published: January 2007

AbstractDie Kristall‐ und Molekularstruktur der Titelverbindung wurde mit Hilfe der Röntgenkristallstrukturanalyse bestimmt. Sie kristallisiert in der monoklinen Raumgruppe P 21/c mit den Gitterkonstanten a = 8,760 Å, b = 26,863 Å, c = 9,678 Å und β = 106,03°. Die Struktur wurde mit der Schweratomtechnik gelöst und mit der Methode der kleinsten Quadrate bis zum R‐Wert von 0,075 verfeinert.
The coherent phase diagram of AIIIBv ternary system
Authors: Kuznetsov V. V. , Sadowski W. , Sorokin V. S. 
Published: January 2007

AbstractThe equations of the coherent phase diagram for AIIIBV ternary system are derived in suggestion of simple solution model. The system Ga‐As‐P is analyzed in details. The solubility of GaP and GaAs in liquid phase Ga‐P‐As of different composition has been investigated. The stabilisation effect of solid solution composition has been quantitatively described using the system Ga‐In‐P.
Energy band‐gap in elastic‐strained heteroepitaxial layers
Authors: Konnikov S. G. , Umansky V. E. 
Published: January 2007

AbstractThe effect of internal elastic stress on energy band‐gap shift in the A3B5 heteroepitaxial layers was investigated. The possibilities to get higher accuracy of divergent beam X‐ray stress determination method, designed in the scanning electron microscope (SEM), was presented. X‐ray topography method in the SEM with X‐ray magnification from 2 up to 10 was for the first time described.The epilayer photoluminescence (PL) peak energy shift as a function of internal elastic stress was measured on the GaInP/GaAs, GAInAsP/InP heterostructures and the influence of different factors on the accuracy of the results was discussed.
The study of the influence of deep level defects on GaAs epilayer electrophysical parameters with electron beam and photoelectron paramagnetic resonance methods
Authors: Bagraev N. T. , Konnikov S. G. , Raitsin A. B. , Sobolev M. M. 
Published: January 2007

AbstractDeep level point defects in the GaAs p+‐pˆ−nˆ structures, grown by liquid‐phase epitaxy, were investigated with electron‐beam methods (electron‐beam induced current and modulation method) and photo‐EPR. It was shown that during the growing process the donor AsGa antisite defects with levels ev + 0.52 eV and ec — 0,75 eV and acceptor defect with the level ev + 0.44 eV have appeared. The interconnection between the thickness of pˆ‐layer, the concentration of deep levels defects, diffusion length of the minority carriers in the p° and n°‐layers was found.
Anomalous thermal expansion of osmium dioxide
Authors: Venudhar Y. C. , Iyengar Leela , Krishna Rao K. V. 
Published: January 2007

AbstractThe precision lattice parameters of osmium dioxide have been determined at different temperatures, in the temperature range 30–444 °C, using a Unicam high temperature powder camera 19 cm in diameter and CuKα radiation. The data have been used to evaluate the coefficients of thermal expansion at various temperatures by a graphical method. The ‘a’ parameter increases non‐linearly with increasing temperature while the ‘c’ parameter remains constant throughout the range of temperature studied indicating a zero coefficient of expansion along the c‐direction. The abnormal thermal behaviour of this compound is explained in terms of the electronic configuration of the d‐shell of the cation.
Microhardness studies on some compound semiconductors
Authors: Nagabhooshanam M. , Babu V. Hari 
Published: January 2007

AbstractVickers microhardness studies on some III–V and II–VI compound semiconductors have been made. The results showed that ZnS has the highest microhardness value. These results are compared with other properties of the crystals such as melting point, ionicity etc. Variation of microhardness with load was also studied on all the crystals. The results indicated that the hardness value increases at low loads. These results have been analysed by using resistance pressure model and interpreted.
Orientation changes during recovery of compressed Mo crystals
Authors: Larikov L. , Belyakova M. , Zakharov S. , Mudruk P. 
Published: January 2007

AbstractThe type of the recovery variety which is accompanied by changes in texture is studied. Reorientation of the surface of compressed Mo crystal was observed during its annealing before recrystallization. As a result, new macroscopic {100} orientation areas appear on the contact crystalline surface of {111} orientation. Turned areas have a more perfect inner structure and correspondingly lesser density of deformation defects. As a result of rotation a high‐angle boundary interface occurs as a “broken boundary”. The transition layer considered is highly stressed and contains microcracks.The boundary interface is shown to be the intensive recrystallization source, where the recrystallization grains are nucleated at the expence of interface dislocation bulgings.The driving forces of the rotation observed and a scheme of a residual stress distribution in the compressed crystal are analysed. According to the scheme a deformed crystalline surface is affected by the compressive stresses and the inner layers are affected by the tensile ones. A relaxation of the internal stresses results from plastic rotations. A rotation moment arising between the surfaces and internal layers of the crystal leads to reorientation.
Thin film diffusion studied by high temperature electron probe microanalysis
Authors: Berndt K. , Karin H. 
Published: January 2007

AbstractDiffusion in Thin Film Systems (TFS) can be studied effectively by means of Electron Probe Microanalysis (EPMA). Using a heating stage in the microprobe the diffusion process in the NiCr/Al TFS was studied by the continuous detection of the Ni‐, Cr‐ and Al‐X‐ray intensity. For the case of long diffusion times and taking into account the specific features of the depth distribution of the excited X‐rays the volume diffusion coefficient, frequency factor and activation energy for the Ni diffusion in Al were determined. Results for NiCrAl interdiffusion will be submitted.
X‐Ray photoelectron valence band spectra from semiconductors Bi2Te3 and Sb2Te3
Authors: Chassé T. , Berg U. 
Published: January 2007

AbstractAngular resolved X‐ray photoelectron spectra (ARXPS) are measured for valence bands of the layer semiconductors Bi2Te3 and Sb2Te3. Starting from simple models taking into consideration the atomic construction, photoionization cross sections and the crystal structure the spectra can be interpreted. Important conclusions are drawn on the electronic structure of these semiconducting compounds.
Investigation of the surface composition changes caused by Ar+‐, N+2‐ and He+‐Ion bombardment of CuNi and AgPd alloys using auger electron spectroscopy
Authors: Heichler W. , Langhammer J. , Zwanzig W. 
Published: January 2007

AbstractThe selectivity of the sputtering process of CuNi and AgPd alloys with different bulk compositions during Ar+‐, N+2‐ and He+‐ion bombardment was studied by the help of Auger electron spectroscopy. It was found that for CuNi alloys a Ni‐enrichment and for AgPd alloys a Pd enrichment takes place compared with bulk composition. The selectivity of the sputtering process decreases with decreasing sputtering ion mass. This result was explained in the case of CuNi alloys on the base of the dependence of elemental sputtering coefficients on the sputtering ion mass.
Crystallization of hydrocarbon (n‐C28H58): Fatty acid (CH3(CH2)14 COOH) mixtures (III). The habit modification
Authors: Prasad P. B. V. 
Published: January 2007

AbstractThe role of n‐octacosane in promoting the growth of fibrous crystals of palmitic acid is studied. The study indicates that (i) adsorption is the probable interaction between the fatty acid and hydrocarbon molecules; (ii) The observed temperature dependence of occurrence of fibrous crystals warrants the adsorption to be a mixture of physisorption and chemisorption and (iii) it is the chemisorption component that is active at elevated temperatures and as a result it promotes the growth of fiber‐like crystals of the fatty acid.
Growth of bis‐dimethylglyoximate Co (III). Single crystals
Authors: Garcia‐Ruiz J. M. , Lopez Martinez C. , Martin‐Vivaldi Cabellero J. L. 
Published: January 2007

AbstractSingle crystals of bis‐dimethylglyoximate Co(III) up to 8 × 6 × 2 mm. in size have been grown by the first time, using diffusion method at room temperature. Optimum size and quality were obtained at pH = 6. These crystals are orange in colour and an X‐ray study shows it to be monoclinic, space group P 21/n, with a = 8.432(4), b = 14.147(3), c = 13.746 (6) and β = 103.78(3)°. The effects of different experimental devices on the growth features are discussed.
Growth and properties of calcium tungstate
Authors: Batra N. M. , Godbole R. S. , Arora S. K. 
Published: January 2007

AbstractCaWO4 single crystals have been grown and compared by three different high temperature solution methods, viz. the normal flux‐cooling procedure, the indirect flux‐reaction technique and the isothermal flux‐evaporation method. The typical as‐grown bipyramidal crystals obtained by these methods have been found to be mostly large and perfect with varying degree of transparency. The crystals are characterised by using EDAX, X‐ray diffraction, electrical conduction, micromechanical tests and chemical etching. The assessment of various characteristics of the grown crystals is likely to show enormous usefulness of the flux grown crystals.
Methods for determination of effective diffusion coefficients in ternary alloys (II). Indirect methods of calculating ternary diffusion matrix
Authors: Malik M. T. , Bergner D. 
Published: January 2007

AbstractWe summarised, in part one of this paper, procedures of measuring diffusion matrix in three‐component single phase alloys direct from the concentration‐distribution profiles in infinite diffusion couples. In this paper (Part II) some procedures have been outlined which enable calculate ternary diffusion matrix from easily measurable tracer coefficients in ideal and non‐ideal single phase solid solutions. These procedures have been illustrated with examples, so that it becomes apparant that in many cases the experimental difficulties faced by the experimentalists in direct measurement of ternary diffusion coefficients can be reduced to a large extent.
Thermotropic Liquid Crystalline Compounds with Lateral Long Chain Substituents (VII). X‐Ray Studies in 1,4‐Bis‐(4‐n‐oetyloxybenzyoloxy)‐2‐n‐alkylbenzenes
Authors: Diele S. , Roth K. , Demus D. 
Published: January 2007

AbstractX‐ray studies in substances with the general formula magnified image in the nematic states were performed. The results prove the existence of cybotactic groups despite the fact that the branched substances do not show smectogenic properties. We propose a model for the packing of the molecules, which explains the influence of the lengths of the lateral branches on the structure of the cybotactic groups.