bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temperature distribution in growing semi‐transparent crystals (II). Comparison of theory with experiments
Authors: Kvapil Jiří , Kubelka J. , Kvapil Josef , Perner B. 
Published: July 2007

AbstractCalculated temperature difference between the liquid/solid interface and bulk of the melt was compared with the wide‐angle scattering (celluae density) of Al2O3 and YAG crystals. Celluae free coloured crystals were grown using higher energy losses from the upper part of the crystal and the melt. Colourless crystals were successfully grown under opposite conditions. The results are in accordance with the calculated temperature differences which are proportional to the actual temperature gradient at the interface.
On the effect of pH of solution on the kinetics of crystallization
Authors: Kuznetsov D. A. , Hodorowicz S. 
Published: July 2007

AbstractA hypothesis has been advanced that thermal vibrations of the molecules and ions in solution excite electromagnetic waves the frequency of which depends, among others, on the concentration of hydroxonium ions. A correlation of the frequency with the vibrations of the molecules in the crystal lattice can affect crystallization rate.
The impurity heterogeneities in the surface layer of silicon with an atomically clean surface
Authors: Aleksandrov L. N. , Lovyagin R. N. 
Published: July 2007

AbstractThe electrical and photoelectrical properties of the surface region of silicon after evaporation in vacuum used in obtaining an atomically clean surface at the subsequent epitaxy are studied. The formation kinetics of a p‐layer at 1300 and 1350 °C for the heating time of 10 to 103 s is investigated. The effective values of holes mobility in p‐layers are independent on a decrease of layer thicknesses down to 0.2μm at the concentration of acceptors of 1017 to 1018 cm−3 (294 K). The concentrations of doping impurities in the surface region of silicon before and after thermal treatment are determined by the method of mass‐spectrometric analysis. The peculiarities of transport and building‐in of doping impurities of the III and V groups at epitaxy and the possible nature of acceptor levels are discussed. A concentration profile of acceptors and donors from the surface deep into the silicon bulk is determined by the methods of layer‐by‐layer etching and of C‐V characteristics. An effective built‐in electric field is due to acceptor and donor distribution, which favours drift separation of minor radiation‐generated current carriers in the p‐n structure. The high‐sensitive and fast‐responding photoreceivers have been produced. The given detectability reaches 2 × 1012 cm Hz1/2/W at a wavelength of 1.06μm.
Kinetics of crystal growth of strontium tungstate from solutions in sodium tungstate melts by continuous cooling
Authors: Roy B. N. , Appalasami S. 
Published: July 2007

AbstractThe crystallisation kinetics of strontium tungstate from unstirred saturated solutions in sodium tungstate melts was studied by continuous cooling from initial crystallisation temperatures T0 = 1000° to 800°C to room temperature at cooling rates RT = 0.67° to 3.3°C min−1. The main crystal growth was diffusion rate‐controlled; the final crystal growth was rate‐controlled by the development rate of excess solute concentration. The estimated diffusion rate constant (kD) values increased with cooling rates and initial crystallisation temperatures. They are higher than the rate constants for diffusion‐controlled growth of calcium tungstate from sodium tungstate melts, but very much smaller than those for strontium tungstate from lithium chloride melts.
Impurity effects on low‐angle boundary formation in silicon single crystals
Authors: Dashevsky M. Ya. , Eidenson A. M. 
Published: July 2007

AbstractThe combined effects of crystal growth conditions and impurity (Sb, P, B, Ga) concentration on low‐angle boundary (LAB) formation in silicon single crystals growing by Czochralski technique was investigated. The dependence of LAB formation frequency and LAB parameters on crystal growth conditions and impurity content was found. Impurity effects on LAB formation become apparent at concentrations of about 1018 cm−3. – All impurity investigated decreases the probability of LAB formation, the acceptor impurity influence is stronger. At B concentration exceeding 2 · 1019 cm−3 LAB formation does not occur. – Results are interpreted in terms of scheme of LAB formation in thermal stress field of growing crystal. To explain observed impurity effects assumptions about dislocation drag and about raising of critical stresses for dislocation generation with doping are made.
Investigation of nitrogen solubility process in silicon carbide
Authors: Lilov S. K. , Tairov Yu. N. , Tsvetkov V. F. 
Published: July 2007

AbstractOn the basis of the epitaxial layers of SiC (N) grown from vapour phase by the sublimation method in a temperature interval (1900–2200) °C and at nitrogen partial pressures from 4 to 760 Torr has been determined the dependence of the nitrogen content in the epitaxial layers of SiC(N) on the nitrogen partial pressure and the temperature of growing. A thermodynamics analysis of the nitrogen solubility process in silicon carbide has been developed taking account of the electron‐hole interaction. The experimental and calculation results, we have obtained, allowed us to determine the partial mol solubility heat of nitrogen in SiC.
Measurement of the shear viscosity in garnet high temperature solutions by a cylindrical rotation viscometer
Authors: Sinn E. 
Published: July 2007

AbstractGarnet high temperature solutions, their solvents and binary systems consisting of lead oxide and one component out of the solute were investigated. The shear viscosity coefficients have been measured in a cylindrical rotation viscometer within the temperature range of liquidus or melting and not exceeding 1270°C. The logarithm of the shear viscosity in the simple systems PbO or PbOB2O3 linearily depends on the reciprocal absolute temperature, however, the relationship in phase systems containing Fe2O3 or Ga2O3 is more complex. The shear viscosities of Y3Fe5O12 or (Y, Sm)3 (Fe, Ga)5O12 solutions suitable for LPE experiments amount 0.20 to 0.23 g cm−1s−1 near the liquidus temperatures. An effective average activation energy for shearing flow was estimated, its dependence on the temperature points to chemical equilibria reactions in the solutions.
Eine neue absolute sin ϕi/sin ϕj‐Methode für die Bestimmung von Gitterparametern
Authors: Vavrda J. 
Published: July 2007

AbstractDie reziproken Quadrate von Gitterparametern werden für ein‐, zwei‐ und dreiparametrige Gitter durch die Lösung von Lineargleichungen ermittelt. Die systematischen Abweichungen werden bei dieser Arbeitsweise total unterdrückt. Die Methode ist für viele Aufnahmenverfahren universell anwendbar.
Effects of doping of Ca and Ba on the dislocation distribution in melt grown KCl crystals
Authors: Inoue T. , Komatsu H. , Takei H. 
Published: July 2007

AbstractThe effects of doping of Ca and Ba (∼ 0.02 at %) upon the dislocation distribution in melt grown KCl crystals without cellular segregation were studied by an etch pit method in connection with the dispersion state of the dopants, which was examined by the dark field illumination. – (1) In the Ca‐doped crystal, in which the dopants were distributed uniformly, the formation of subboundaries was completely suppressed and dislocations were distributed at random. (2) In the Ba‐doped crystal, however, the dopants were non‐uniformly distributed and the dislocations tended to form subboundaries. The dislocations within the subgrains were distributed in a non‐uniform manner. (3) The dislocation density in the Ba doped crystal was higher than that of undoped or Ca‐doped crystal. This was explained by the mechanism similar to the Tiller's prediction. – Finally, the stress distribution due to the concentration fluctuation was examined by the birefringence patterns.
Crystal growth of potassium perchlorate in gelatin gels
Authors: Patel A. R. , Rao A. Venkateswara 
Published: July 2007

AbstractThe suitability of gelatin gel for the growth of good quality single crystals of potassium perchlorate has been investigated. Growth in a more rigid and simple apparatus has been accomplished and described here. The grown crystals were identified by X‐ray analysis. A study of the relation of crystal morphology to concentration of feed solutions and growth temperature has also been made. Studies made on chemical etching of the cleavages have revealed that the crystals are relatively perfect. At times, large liquid inclusions which introduce stresses in the crystals are responsible for a large dislocation concentration.
Oxidation kinetics of BaF2 single crystals
Authors: Aronova A. M. , Berezhkova G. V. 
Published: July 2007

AbstractOxidation of BaF2 single‐crystals as a result of annealing in air in the temperature range 600° to 900 °C leads to mechanical strengthening. The process kinetics was investigated. It is shown that oxidation takes place in the bulk of crystals owing to oxygen diffusion by formation and growth of oxidation centres. These centres are precipitates of a BaO phase which were revealed by chemical etching.
Thin thermosensitive film coating
Authors: Komitov L. , Hiebaum G. 
Published: July 2007

AbstractThin film thermosensitive coatings are obtained, representing liquid crystal microdroplets dispersed in a polymeric matrix. Gelatin is chosen as a polymeric material. The obtaining of microdroplets is carried out by condensation of the solution of liquid crystal in organic solvents at their mixing with gelatin aqueous solution. The obtained coating distinguishes with temperature stability, homogeneity of the colouring, stability of the time indicators.
Cold rolling texture development in Zn, Cd and Mg
Authors: Ivaniji V. S. , Moroz I. A. 
Published: July 2007

AbstractStudied are the regularities of preferred orientations in the process of rolling of zinc, magnesium, and cadmium. On the basis of the data obtained and analysis of crystallographic mechanism of Cd, Zn and Mg crystals a “dynamic” model of the rolling texture formation in zinc and cadmium as well as a “monotonic” one in magnesium are suggested.
H3PO4 — etching of {001}‐faces of InP, (GaIn)P, GaP, and Ga(AsP)
Authors: Gottschalch V. , Heinig W. , Butter E. , Rosin H. , Freydank G. 
Published: July 2007

AbstractThis paper shows that hot H3PO4 is a suitable etchant for the production of dislocation etch pits on {001}‐InP, (InGa)P, GaP, Ga(AsP), and {111}‐GaP. The effects upon etch pit morphology of the misorientation of samples and the type of dislocations are investigated in detail.
Investigation of 1 S1/2O,1 S1/2C and 2 P3/2Ni states of argon ion implanted nickel metal
Authors: Gumanski G. A. , Chodasewitsch V. V. , Brümmer O. , Wagner N. 
Published: July 2007

AbstractPolycristalline Ni samples were bombarded by 30 keV Ar ions with dose rates from 1016 ions/cm2 to 1017 ions/cm2. The investigation of the electronic states 1 S1/2O, 1 S1/2C and 2 P3/2Ni was made by X‐ray photoemission spectroscopy (XPS). The XPS core level spectra show features refering to different chemical compounds of oxygen and carbon with nickel. We have studied the change of this spectrum structure dependent on distance of the sample surface for various doses of implantation.
On the interpretation of the determination of particle size and distortion of crystallites with a screw dislocation
Authors: Röll H. 
Published: July 2007

AbstractFor an infinitely long cylindrical crystallite with an axial screw dislocation the roentgenographic distribution function of distortions is calculated. This distortion distribution essentially differs from the Gaussian distribution underlying the Warren‐Averbach procedure by a dependence on the Fourier order, a maximum with distortions different from zero, as well as a cutt‐off radius reciprocally proportional to the Fourier order. Further it is shown that for the mentioned distortion model the conception of a particle size independent on the Fourier order is correct.
Zur Bestimmung der Kristallitgrößenverteilung von Metallen auf Katalysatorträgern aus Röntgenweitwinkelmessungen (II). Direktberechnung von Kristallitgrößenverteilungen aus Röntgenbeugungsprofilen
Authors: Spindler H. , Ackermann W.‐G. 
Published: July 2007

AbstractEs werden Verfahren angegeben, welche die Sehnenlängenverteilung — bzw. bei kugelförmigen Teilchen auch die Durchmesserverteilung — von Metallkristalliten in Trägerkatalysatoren ohne Differentiation direkt als Transformation von Funktionen zu berechnen gestatten, die unmittelbar aus den Intensitäten von Röntgenweitwinkelinterferenzen abgeleitet werden. Es wird gezeigt, daß zur Beschreibung des Kristallwachstums das erste Moment der Sehnenlängenverteilung geeignet ist. Für das Wachstum von Platinkristallitenin PtAl2O3‐Katalysatoren wurde in inerter Atmosphäre ein Zeitgesetz 2. und in oxydierender Atmosphäre ein Zeitgesetz 4. Ordnung gefunden.
On the decomposition behaviour of Al‐Zn(4.5 at.%)‐Mg(2;3 at.%) alloys during continuous cooling from the temperature range of homogeneity
Authors: Radomsky M. , Kabisch O. , Löffler H. , Sackewitz K.‐H. , Honyek G. , Ungár T. , Lendvai J. , Kovács I. 
Published: July 2007

AbstractThe decomposition processes taking place in the Al‐Zn (4.5)‐Mg(2;3) alloys were studied by means of XSAS and resistivity measurements and by TEM investigations after continuous slow cooling to certain temperatures Ti and during an isothermal ageing at Ti following the continuous cooling procedure. During the cooling between 380 °C and 320 °C mostly particles of the η‐phase are growing. The formation of particles homogeneously distributed in the matrix starts at 165 °C in the alloy with 2 at.% Mg and at 175 °C in the one with 3 at.% Mg. Below these temperatures new subcritical GP zones are formed and particles already present in the matrix are growing. The dominating process depends on Ti.
Epitaxial layers of CuGaTe2 on GaAs
Authors: Schumann B. , Tempel A. , Kühn G. , Neumann H. , Peters D. , Hörig W. 
Published: July 2007

AbstractCuGaTe2 thin films with thicknesses in the range from 0.1 to 0.2 μm were deposited onto semi‐insulating (111) A‐oriented GaAs substrates by flash evaporation under controlled growth conditions. Epitaxial growth begins at a substrate temperature of Tsub = 695 K. In the range Tsub = 695 … 820 K the films have the chalcopyrite structure, at Tsub = 820 to 840 K a second phase was observed besides the chalcopyrite phase. At Tsub > 840 K the films become polycrystalline. All epitaxial films were p‐type conducting and showed an increase of the hole concentration with rising substrate temperature. The measured mobilities indicate to the presence of a high concentration of neutral impurities or defects.
On the mechanical stresses caused by growth centers
Authors: Malicskó L. 
Published: July 2007

AbstractThe question of the development of mechanical stresses in crystals during their growth is investigated. The mechanical stress field is calculated which can be caused by a radially inhomogeneous impurity concentration distribution existing around growth centers. For the case of KCl: Pb crystals it is shown that depending on growth condition these stresses can be very considerable.
Determination of the crystallite size in epitaxial layers of PbTe by means of X‐ray diffraction rocking curves
Authors: Schäfer P. , Berger H. 
Published: July 2007

AbstractTo prove the influence of the crystallite size (dimension of coherent regions parallel to the reflecting lattice planes) on the rocking curve of single crystals, half widths measured on epitaxial layers of PbTe have been evaluated. It results from statistical analysis of the data that there exist a significant influence of the crystallite size. The crystallite sizes have been calculated from these data using two simple models. The values have orders of magnitude as expected and agree with data from electron microscopy. The method as described here can be applied in suitable cases to get an additional parameter for characterizing the structural perfection.
Microscopy with an ellipsometric arrangement
Authors: Löschke K. 
Published: July 2007

AbstractA method is given to observe a sample with an ellipsometer equipment allowing a microscopical observation of a reflecting surface. The microscopical images are contrasted by the elliptical polarization and reflect the inhomogeneity of the optical properties of the surface. The contrast is of the high resolution of the ellipsometrical method registrating very low variations of optical properties of the reflecting sample. In this paper we give par example an observation of a step of a native oxide film on GaAs of only three Ångstroms.
Physical Properties of Pb0.8Sn0.2Te :In Epitaxial Layers
Authors: Kaljuzhnaya G. A. , Mamedov T. S. , Herrmann K. H. , Wendt M. 
Published: July 2007

AbstractA study was made of dislocation density, Hall effect, conductivity, and photoeffects in In‐doped Pb0.78Sn0.22Te epitaxial layers. From an analysis of RH vs T the existence of resonant as well as deep levels is concluded, dependent on In content and defect structure. Samples with about 0.4 at.% In which are not compensated, exhibit photoresponse as well as luminescence.
Dielektrische Eigenschaften und Phasenübergänge von M2SbF5 ‐Kristallen
Authors: Grigas J. , Dawidowitsch R. , Petscheliunaite A. , Urbonawitschius W. 
Published: July 2007

AbstractIn der vorliegenden Arbeit sind die Ergebnisse der Untersuchung der dielektrischen Eigenschaften und elektrischen Leitfähigkeit von M2SbF5‐Kristallen dargestellt. In diesen Kristallen wurden kleine Anomalien der niederfrequenten ϵ′yy, ϵ″yy‐Werte und elektrischen Leitfähigkeiten, die auf die Phasenübergänge hinweisen, gefunden. Es wird das Wesen dieser Phasenübergänge diskutiert.
Effective Nucleation Rate in Size Dependent Growth Systems
Authors: Rojkowski Z. 
Published: July 2007

AbstractUsing of MSMPR technique for simultaneous obtaining crystal growth and nucleation data poses a problem in the case of size dependent growth systems. Namely, the necessary extrapolation of experimental population density plot down to zero size is dubious because of its very steep and varying slope. Thus only some effective nucleation rate can be determined accurately. The proposed method of calculating it comprises cutting population plot at some effective size Le chosen as a fraction of dominant size of mass weighted CSD of product from MSMPR crystallizer. Such a point of reference enables to compare nucleation rates even of different systems. Correlations of experimental data for aluminium ammonium alum are presented.
Zur Beeinflussung von Tracht und Habitus von Harnstoffkristallen (I)
Authors: Gaedeke R. , Wolf F. , Bernhardt Gudrun 
Published: July 2007

AbstractEs konnte gezeigt werden, daß Harnstoff beim Kristallisieren aus wäßrigen Lösungen mit NH4Cl Mischkristalle, Adsorptionsmischkristalle und epitaktische Aufwachsungen ausbildet. Das Ausmaß der Mischkristallbildung wird durch die Zusammensetzung der Ausgangslösungen bestimmt. Die Harnstoff/NH4Cl‐Mischkristalle wirken im Sinne von Morphologiewandlern auf Tracht und Habitus des auskristallisierenden Harnstoffs, wodurch anwendungstechnische Vorteile bezüglich Transport‐ und Lagereigenschaften resultieren.
Dendritic Growth of Potassium Dihydrogen Phosphate Crystals in Silica Gels
Authors: Joshi M. S. , Antony A. V. 
Published: July 2007

AbstractDendritic growth of potassium dihydrogen phosphate (KDP) crystals in silica gels at room temperature is reported. Branching along directions perpendicular to the arms and dendrites growing in mutually perpendicular 〈100〉 and 〈010〉 directions are illustrated. Initial stages and surface of a dendrite are illustrated and described. Also explained are the crystallites growing on the dendrite which finally lead to the formation of platelets.
Measurement of Microcrystal Size by Means of Diffraction of X‐Rays
Authors: Pučálka V. 
Published: July 2007

AbstractThe diffraction function expressing the dependence of the intensity of the diffracted X‐rays on the angle of diffraction ϱ is derived. On the basis of this equation two methods of measuring the microcrystal size in the direction of the normal line onto the beam of coherently diffracting atom planes are elaborated. Further, the methods for measuring the diffraction line enlargement owing to the experimental conditions are given here.
Crystal and Molecular Structure of Non‐hydrated and Hydrated Piperidinium‐acet‐o‐Cl‐anilide‐chloride
Authors: Reck G. , Kretschmer R. G. 
Published: July 2007

AbstractCrystallizations from water and alcoholic solution respectively yield different crystal and molecular structures of Piperidinium‐acet‐o‐Cl‐anilide‐chloride. The non‐hydrated compound crystallizes from alcoholic solution in the space group P 21/c with 4 formula units C13H18N2OCl2 in the unit cell of dimensions a = 12.352 Å, b = 6.864 Å, c = 19.018 Å and β = 113.98°. The hydrated modification has the space group C 2/c with 8 formula units C13H18N2OCl2 and 8 H2O molecules in the unit cell. The lattice constants are a = = 24.159 Å, b = 8.966 Å, c = 14.179 Å and β = 90.50°. The X‐ray structure analyses were carried out to investigate the hydrogen bonds and the change of the molecular conformation caused by linking of water molecules to the drug molecules.
The Crystal Structure of 3‐Methoxy‐estra‐1,3,5(10)‐triene‐16α Br,17β OH
Authors: Szulzewsky K. , Seidel I. 
Published: July 2007

AbstractThe steroid 3‐Methoxy‐estra‐1,3,5(10)‐triene‐16αBr,17βOH crystallizes in the tetragonal space group P 41 with the lattice constants a = b = 10,358(2) Å, c = 32,591(5) Å. The crystal structure contains two symmetry independent molecules. Significant differences for the two molecules occur in all the four rings of the steroid sceleton. The molecules are linked by hydrogen bridges and Br…︁ Br contacts. The differences between the two symmetry independent molecules are interpreted as due to different intermolecular interaction.
Investigation of Semiconductor Materials and Devices by High Voltage STEM Techniques
Authors: Cosslett V. E. , Fathy D. , Sparrow T. G. , Valdrè U. 
Published: July 2007

AbstractThis paper reviews work carried out in‐situ on semiconductor devices by means of a high voltage electron microscope equipped with facilities for scanning transmission electron microscopy, electron beam induced conductivity and energy loss spectrometry. These combined techniques have allowed simultaneous and unambiguous correlations to be established between crystallographic, electrical and elemental properties of semiconductor materials and devices. Examples of these correlations are given, and mention is made to facilities (scanning deep level transient spectroscopy and cathodoluminescence) which may further increase the potential of high voltage scanning transmission electron microscopy.
High Temperature In‐situ Investigation in HVEM — Deformation, Irradiation, and Recrystallization. Instrumentation and Applications to Materials Science
Authors: Valle R. , Benty G. , Marraud A. 
Published: July 2007

AbstractHigh temperature in‐situ experiments not only require a conventional equipment, but also special devices such as a double tilting straining holder, a double tilting heating holder (1500 K), a high vacuum specimen chamber (a few 10−6 P ≅ 10−8 Torr) and a low light level, high resolution, visualization and recording system.Some preliminary conclusions, regarding the representativeness of the in‐situ experiments in HVEM, may be derived from the recrystallization and deformation tests performed at ONERA. The fact that the results of these experiments are in good agreement with those obtained through macroscopic tests, a posteriori demonstrates that the former experiments are representative of the bulk material.