bluuebunny/crossref_metadata_2025_split huggingface dataset:
ESCA‐Untersuchungen an anodisch oxydierten AIIIBV‐Verbindungen
Authors: Bilz H. J. , Leonhardt G. , Kühn G. , Löschke K. , Meisel A. 
Published: July 2007

AbstractDurch schrittweises Abtragen von anodisch erzeugten Oxidfilmen auf GaP, GaAs, GaSb und InSb durch Ar+‐Ionenbeschuß wurden Tiefenprofile erhalten. In allen Fällen wurde festgestellt, daß die Übergangszone zwischen Halbleiter und Oxid mehrere hundert Ångström beträgt. Ebenso wurden die Bindungsenergien der Komponenten bestimmt. Im Gegensatz zu den thermisch oxydierten Proben sind im Film nur oxydierte AIII und BV‐Komponenten nachgewiesen worden.
Untersuchungen zur Wachstumskinetik von Oxidschichten auf polykristallinem Wismut mit Hilfe der Röntgenphotoelektronenspektroskopie
Authors: Wagner N. , Brümmer O. 
Published: July 2007

AbstractPhotoelektronenspektroskopische Untersuchungen ergeben, daß auf einer polykristallinen Wismut‐Oberfläche ein dickenbegrenztes inhomogenes Schichtenwachstum einer Sauerstoffschicht erfolgt. Das Material wurde unter definierten Bedingungen im Labor ausgelagert. Die Wachstumskinetik wird durch einen Mehrstufenprozeß bestimmt, hervorgerufen durch lokale Unterschiede im Kontaktpotential zwischen Metall und Metalloxid. Die Unterschiede entstehen durch eine inhomogene Verteilung von Leerstellen im Kationengitter des Bi2O3. Diesen Schlußfolgerungen liegen in den Anlaufbereichen des Schichtenwachstums der Mott‐Cabrera‐Mechanismus, in den „Sättigungs”︁ bereichen ein logarithmisches Wachstumsgesetz zugrunde. Die Modelle gestatten eine gute Beschreibung der experimentell bestimmten Wachstumsparameter.
Preparation and some properties of thallium orthothioarsenate single crystals
Authors: Olexeyuk I. D. , Babidorich P. I. , Rez I. S. , Voroshilov Yu. V. 
Published: July 2007

AbstractGrowing of large (Ø 25–30 mm, L = 50–60 mm) optically homogenous single crystals of Tl3AsS4 using the Bridgman‐Stockbarger method is described. Tl3AsS4 is orthorhombic (Pnma), a = 8.85 ± 0.03, b = 10.86 ± 0.03, c = 9.18 ± 0.03 Å; z = 4; ϱx = 6.15 g · cm−3; ϱp = 6.15 ± 0,03 g · cm−3, Tm = 424 ± 3°C, Moh's hardness = 3, microhardness and ultrasonics velocity along x, y, z are 65–85 kg · mm−2 and 2.16 – 2.37 · 105 cm · sec−1, respectively. The crystals possess perfect cleavage plane (010). Their transparency range is 0.6–12 microns. – Unsuccessful attempts to obtain Tl3AsS4 and its alloys in the vitreous state were taken. The possibilities of glass formation and boundaries of the vitreous region in the system Tl–As–S based on the characteristic features of the melt forming structural units are analyzed.
Sulphosalt minerals: Crystal chemistry and morphology
Authors: Kostov I. 
Published: July 2007

AbstractPolymerization of semi‐metallic R2S3 and metallic (M2+M2+)S structural units leads to step‐like change of chemical composition of the sulphosalts and to morphology which is pronouncedly planar for the sulpharsenides, pseudoisometric for the sulphantimonides, and axial for the sulphobismuthides. Isomorphous substitution is very restricted both for semi‐metals and metals.
Zum Sprödverhalten von Muskovit
Authors: Becherer G. , Sitarek U. 
Published: July 2007

AbstractAuf der Basis der linearen anisotropen Elastizitätstheorie wurden Energiefaktoren K und Energieparameter Kb von möglichen Versetzungen in Muskoviteinkristallen analytisch berechnet. Dabei wird Muskovit entsprechend den elastischen Konstanten als hexagonaler Kristall angesehen. Mit den Energieparameterwerten der angenommenen Gleitsysteme wird das Sprödverhalten des Muskovits erklärt.
Regelungsvorgänge beim Verdichten von Sylvin‐Pulver in Glattwalzenwerken
Authors: Nguyen M. M. , Siemes H. 
Published: July 2007

AbstractSylvinpulver wird in Glattwalzenwerken zu plattigen Körpern zu sog. Schülpen verarbeitet. Bei diesem Vorgang werden die Sylvinkörner zusammengepreßt und verformt bis der Porenraum nahezu verschwunden ist. Die zunächst würfelförmigen Körner werden durch die Verformung ± linsenförmig und nehmen Vorzugsorientierungen an. In den oberflächennahen Schichten der Schülpen bildet sich unter dem Einfluß einer Scherverformung eine Vorzugslage mit {111} parallel zur Scherebene (= Walzebene) und 〈011〉 + 〈112〉 parallel zur Scherrichtung (= Walzrichtung) und eine zweite mit {100} parallel zur Scherebene und nur 〈011〉 parallel zur Scherrichtung aus. In den inneren Schichten stellt sich eine achsialsymmetrische Regelung mit {100} senkrecht zur Walzebenennormalen ein.
Röntgenographische Untersuchungen zum Abbau von bleihaltigen Stabilisatoren im PVC
Authors: Martius G. , Brand P. 
Published: July 2007

AbstractRöntgenographische Untersuchungsmethoden können nicht nur zur Charakterisierung technischer kristalliner Zusatzstoffe für Plaste herangezogen werden. Im Falle der Stabilisatoren zweibasisches Bleistearat und dreibasisches Bleisulfat im PVC wird gezeigt, daß man den Abbau dieser Stoffe bei thermischer Beanspruchung des Materials durch Anfertigung von Diffraktogrammen erfassen kann, wobei basische Bleioxichloride als kristalline Zwischenstufen erkennbar werden. Als Endprodukt der Reaktion der Bleistabilisatoren mit dem bei der Spaltung des PVC freigesetzten HCl entsteht Bleichlorid, wobei auch die Umsetzung des Sulfatanteils des dreibasischen Bleisulfats in dieser Verbindung in Betracht gezogen werden muß. Die Intensitäten der Interferenzen des dreibasischen Bleisulfats und des Bleichlorids auf den Röntgendiffraktogrammen gestatten den Abbauzustand des Werkstoffes nach einem mit einer thermischen Beanspruchung verbundenen Verarbeitungsprozeß einzuschätzen. Es besteht auch die Möglichkeit, die thermische Stabilität verschiedener bleistabilisierter PVC‐Materialien miteinander zu vergleichen.
Tempern von Cd0,2Hg0,8Te im Quecksilberdampf
Authors: Dittmar G. , Forbrig B. , Schubert F. 
Published: July 2007

AbstractAls Ausgangsmaterial für hochempfindliche Infrarot‐Fotowiderstände wird n‐leitendes Cd0,2Hg0,8Te mit minimaler Ladungsträgerkonzentration und maximaler Ladungsträgerbeweglichkeit benötigt. Durch Tempern im gesättigten Quecksilberdampf kann die Zahl der Defekte, die bei der Kristallzüchtung im Cd0,2Hg0,8Te entstanden sind wesentlich verringert werden. Es werden Einzelheiten der Vorbereitung und Durchführung der Temperversuche sowie experimentelle Ergebnisse beschrieben.
Review of the X‐ray diffraction in extreme asymmetric cases
Authors: Härtwig J. 
Published: July 2007

AbstractThe differences in the theoretical treatment of extremely asymmetric cases in comparison with the conventional dynamical theory of X‐ray diffraction for the perfect crystal are shown and based. Some theoretical results for the four extremely asymmetric cases are presented and discussed. The limit of the conventional theory and the applicability of some of its results in the case of extreme asymmetry are stated.
Quantum mechanical relations in interface processes at electrode systems of the second kind
Authors: Winzer A. 
Published: July 2007

AbstractIt is shown that the difference of the electrochemical standard potentials between Ag/AgCl(s), KCl (aq, a = 1 mole l−1) and Ag/AgBr(s), KBr (aq, a = 1 mole l−1 can be attributed to the ion exchange from the AgCl phase to the AgBr phase. In this process, quantum mechanical relations play an essential part. A relation derived from Einstein's equation for calculating the inner energy of an ionic crystal and from the AC‐Josephson equation allows the calculation of the difference of the electrochemical standard potentials between the electrode systems Ag/AgCl(s), Cl−‐Ag/AgBr(s), Br−; Cu/CuCl(s), Cl−‐Cu/CuBr(s), Br− and Hg/Hg2Cl2(s), Cl−‐Hg/Hg2Br2(s), Br− from the frequency of the longitudinal optical phonons. An equation for the quantum mechanical calculation of the nernst factor (RT/zF) in the so‐called Nernst equation is given. Thus, the structural parameters of the respective solid state electrodes are in close relation with the transport processes in electrode systems of the second kind.
Orientational order of dissolved molecules in the nematic, smectic A and smectic B phases of 4‐n‐hexyloxybenzylidene‐4′‐n‐hexylaniline
Authors: Pelzl G. , Vetters D. , Demus D. 
Published: July 2007

AbstractThe orientational order S of a dichroic dye dissolved in a liquid crystal has been determined in the nematic, smectic A and smectic B phase of 4‐n‐hexyloxybenzylidene‐4′‐n‐hexylaniline. The used method is based on the absorption measurement of unpolarized light in a homeotropic oriented liquid crystalline layer and in an isotropic layer. The orientational order of the dissolved molecules was compared with the order parameter of the liquid crystalline solvent.
Indentation deformation of magnesium orthosilicate single crystals
Authors: Desai C. C. , John V. 
Published: July 2007

AbstractThe variation in the microhardness of the magnesium orthosilicate crystals has been determined using Vicker's microhardness indentor. The length of the rays of dislocation rosettes around the indentation, obtained by etching the indented cleavages have been measured. 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, and (iii) the microhardness of the crystal is independent on the duration of loading. The implications are discussed.
Jump‐like twin boundary movement in indium crystals
Authors: Fomenko L. S. 
Published: July 2007

AbstractThis is an investigation of the specific features of twin boundary movement by creep in indium crystals at room temperature. It has been shown that in the most structurally perfect crystals, broadening of twin layers is jump‐like. Jumps in the kinetic relations for boundary displacement are the most pronounced in the stress range where the initial boundary velocity becomes as high as (5 × 10−5–10−4) cm/s. The effect of the applied stress on the average jump density and the characteristic boundary motion velocities, that is the initial velocity, the velocities at the jump and just before it were investigated. Dislocation structure deterioration as well as impurity increase lead to changes in the boundary motion character, namely to monotonic reduction of boundary velocities with time. It has been ascertained that the jump‐like nature of the boundary motion is due to boundary interaction with obstacles present in the crystal and unambiguously associated with periodically changing boundary structure: defect formation and eventual defect inclusion into the twinned material.
Transport Coefficients and Structural Principles of PbOGa2O3 Melt
Authors: Fischer K. , Linzen D. , Sinn E. , Stieff H. , Voigt F. 
Published: July 2007

AbstractMore Precise knowledge of the growth mechanism of garnets in form of epitaxial layers or single crystals in high temperature solutions on the base of trivalent oxides Me2O3 in PbOB2O3 solvent is desirable. Data of physicochemical properties of the melts especially density, shear viscosity, and electrical conductivity and their dependence on the temperature are useful in endeavour to recognize the structural principles of oxidie melts. Therefore as a first step the binary system PbOGa2O3 was investigated to understand the influence of the Ga component on a complete mixed garnet solution, for instance (Y, Sm)3 (Fe, Ga)5O12 in PbOB2O3 solvent.
The Distribution of Thorium in Fluorite Single Crystals
Authors: Nistor L. C. , Nistor S. V. , Teodorescu V. , Voicu I. 
Published: July 2007

AbstractSingle crystals of CaF2 doped with ThO2 were grown by the Czochralski‐Kyropoulos technique in graphite crucibles. The distribution of thorium in the as grown crystals has been investigated by optical and transmission electron microscopy, selected area diffraction and optical spectroscopy.
α‐substitued phosphoryl compounds (IV). The crystal and molecular structure of diethyl[bis‐(p‐chlorophenoxy)‐methan]‐phosphonate, C17H19O5PCl2
Authors: Kulpe S. , Seidel I. 
Published: July 2007

AbstractDiethyl‐[bis‐(p‐chlorophenoxy)‐methan]‐phosphonate crystallizes in the triclinic space group P 1 with two molecules per unit cell. The lattice parameters are a = 8.757 Å, b = 10.479 Å, c = 12.878 Å, α = 82.21°, β = 116.27°, γ = 113.80°. With X‐ray diffraction data, collected on an automatic four circle diffractometer, the crystal structure was solved by direct methods and refined to an R‐value of 0.049 for 3116 measured and symmetrically independent reflections. The substance is a derivative of acetales of formyl phosphonic acid esters. Correlations between the geometry of the structure and NMR‐data are of interest.
Influence of the revolution number of the stirrer in viscous liquid on the crystal mass growth rate
Authors: Malczewski J. 
Published: July 2007

AbstractThe relative velocity between crystal and viscous solution has significant influence on the crystal mass growth rate. In this article a horizontal crystallizer with a stirrer is considered. It appears that in the case of laminar flow of viscous liquid, the relative velocity between crystal and solution doesn't depend on the revolution number of the stirrer and is approximately equal to the settling velocity of the crystal.
Growth and electrical properties of liquid phase epitaxial layers of GaxIn1‐xP lattice‐matched to GaAs substrates
Authors: Penndorf J. , Kühn G. , Neumann H. , Müller A. 
Published: July 2007

AbstractFrom the measurement of the evaporation rate of phosphorus the favourable conditions for the layer growth were determined. Further, we have studied the influence of zinc and silicon on the growth and the morphology. The mobilities, the electron and hole concentrations in the temperature range from 77 to 300 K are presented. In the Si‐doped samples we could not find a correlation between the silicon concentration in the melt and the donor concentrations in the layer. An estimation of the acceptor ionization energy in Zn‐doped samples yields EA = (15 ± 4) meV.
Etching studies of tungstenite (WS2) crystals in acids
Authors: Agarwal M. K. , Reddy K. Nagi 
Published: July 2007

AbstractSingle crystals of tungstenite (WS2) have been grown by direct vapour transport or sublimation method. An etchant capable of revealing the sites of dislocations has been developed. The effects of etching time, etchant concentration and temperature on the selective etch rate have been worked out. It is seen that the etch rate is independent on time, but is influenced by the temperature and concentration of the etchant. The values of activation energy determined from the etch rate against temperature plots established that the process of etching in chromic acid is chemical reaction rate controlled. The effect of addition of HF to the above etchant has led to some further interesting results.
New experimental results on nucleation of Au on NaCl: Dependence on deposition rate and time
Authors: Stenzel H. , Velfe H. D. , Krohn M. 
Published: July 2007

AbstractSystematic experiments have shown that saturation density, nucleation rate, and condensation coefficient are considerably smaller than previously reported. The low condensation coefficient and the linear deposition rate dependence of the nucleation rate show that the model usually applied for the theoretical explanation of the nucleation process needs some revision. From measured condensation coefficients we have estimated the diffusion length of adatoms, xs = (14.4 ± 2.4) nm, and the difference between desorption and diffusion energy, Ea – Esd = (0.31 ± 0.01) eV. Possible reasons for the deviation of the new results from the earlier ones are discussed.
Growth of CaMoO4 and SrMoO4 crystals in silica gel media
Authors: Kurien K. V. , Ittyachen M. A. 
Published: July 2007

AbstractGrowth kinetics and characterization of calcium and strontium molybdate crystals grown in silica gel have been studied under a variety of parameters. The changes in nucleation characteristics, growth habit, quality of these crystals were carefully observed and are found directly related to pH of the medium. The profound influence of pH on spontaneous crystallization of CaMoO4 crystals has been carefully investigated; and its crystallization range has been determined. The wide morphological change of SrMoO4 with respect to pH variation has been studied. The quality of the crystals has been critically examined.
The influence of the dislocation density on the sulphur segregation at the Ni(110) surface in the course of heating
Authors: Storbeck F. , Heyn T. , Auleytner J. , Jasiolek G. 
Published: July 2007

AbstractThe segregation of sulphur of the surface from Ni(110) monocrystals has been studied by LEED and AES. We have founded that the diffusion is dependent to the temperature and the dislocation density and we interpret this observation with the diffusion along the dislocations and the volume diffusion.
Information gain from analytical description of isothermal resistivity curves
Authors: Oettel W. , Radomsky C. , Löffler H. 
Published: July 2007

AbstractThe experimentally gained course of the resistivity of some Al‐Zn‐Mg alloys during isothermal aging is analyzed by means of a calculation of the extra resistivity of GUINIER‐PRESTON zones based on the solution of the BOLTZMANN‐equation in the isotropic relaxation time approximation and using XSAS intensities quoted by GUINIER and FOURNET.Applying this equation from the increase of the resistivity information on the time development of the volume fraction of the zones and from the course of the resistivity behind the maximum the growth law of the precipitates can be drawn from the alloys investigated.
XPS investigations of Ti‐supported Pt‐Ir catalytic systems
Authors: Wagner N. , Brümmer O. 
Published: July 2007

AbstractSome XPS‐spectra (core levels and valence bands) of Ti supported active layers (Pt0.7Ir0.3) on various catalytic activity were investigated. Not only the mentioned species were studied but also the impurity elements oxygen and carbon. All data given below are dependent on the information depth (maximum ∼ 13 nm). The various reactivity can be described quantitatively as well as qualitatively by XPS data. Concerning this the relative change of composition in the surface region is very important.
Growth of single crystals of NaCl in Gels
Authors: Desai C. C. , Rai J. L. 
Published: July 2007

AbstractThe growth of transparent single crystals of sodium chloride (NaCl) in agar and silica gels up to 4 × 4 × 4 mm size is reported. A brief description of the material preparation, growth procedure and crystal nucleation is given. Hydrochloric acid was used to crystallize NaCl incorporated in the gel which reduces the solubility of NaCl in the gel media. Crystalline perfection has been studied using the chemical etching method.
Influence of impurity and indentation time on dislocation rosettes
Authors: Boyarskaya Yu. S. , Kats M. S. , Zhitaru R. P. , Linte M. A. 
Published: July 2007

AbstractIt has been shown that the impurity type and indentation time affect appreciable on dislocation rosettes of NaCl single crystals. It was established that the growth of indentation diagonal was not practically followed by the increase of the dislocation zone size. This phenomenon connected with the cross slip processes, which are perhaps more intensive for prolonged indentation time and high temperatures. The assumption is made that the two mechanisms of responsible for indentation formation the movement of dislocations and their multiplication by the cross slip.
The growth kinetics of barium sulphate crystals in suspension: Scale prevention (I)
Authors: van Rosmalen G. M. , van der Leeden M. C. , Gouman J. 
Published: July 2007

AbstractThe growth process of barium of sulfate crystals suspended in a supersaturated solution has been studied conductometrically. The mean linear rate R̄ has been plotted as a function of the growth affinity — Δμ/RT. A first attempt has been made to fit the experimental growth data in the highest supersaturation range with surface nucleation models.
The precipitation of lead sulphate from aqueous and aqueous alcohol solutions: Nucleation, final sizes and morphology
Authors: Packter A. , Alleem A. 
Published: July 2007

AbstractThe precipitation of lead sulphate was studied from 0.0001 to 0.01 M aqueous solutions (supersaturations 3 to 600) and from 20% aqueous ethanediol, methanol and ethanol solutions, in polypropylene beakers, at ambient temperature: the experimental techniques were conductivity measurements and optical microscopy. The precipitations were heterogeneously nucleated at low supersaturations and homogeneously nucleated at intermediate to high supersaturations. New crystal morphologies generally developed at some what higher supersaturations in the aqueous alcohol systems. The final crystal lengths at first increased with increasing initial metal salt concentration and then decreased with this parameter; the largest crystals at any concentration were obtained from solutions in which lead sulphate solubility was highest. The critical supersaturations (for the onset of homogeneous nucleation) increased from 36 (in water) to 50 (in 20% aqueous ethanol): the surface energies for the formation of nuclei correspondingly increased from 90 to 110 mJ m−2 in good agreement with the Nielsen‐Söhnel relation. The nucleation and crystal growth processes are taking in an aqueous environment of similar water activity to that of the bulk solutions.
X‐ray trajectories in crystals with x‐depending deformation gradients
Authors: Dietrich B. , Härtwig J. 
Published: July 2007

AbstractBased on the Eikonal theory analytical solutions of the trajectory‐equation were calculated for some special x‐depending deformation gradients, where x shows in the direction of the diffraction vector. For the discussion deformation gradients are chosen which are similar to those in crystals with varying concentrations of impurity atoms. The calculated trajectories allow to obtain properties of section‐ and traverse‐topographs.
Connection between electrical and deformation characteristics of PbS crystals
Authors: Milevskii L. S. , Tkacheva T. M. , Urusovskaya A. A. , Knab G. G. 
Published: July 2007

AbstractThe influence of plastic deformation on temperature dependence of carrier concentration n and mobility μ in PbS crystals has been studied. Comparison of the results obtained with selective etching patterns from original and deformed crystals makes it possible to conclude that during the plastic deformation there takes place a dissolution of precipitates by passing of dislocations through them. As a results, rows of point defects appear along the path of dislocation movement which may be the cause of a change in n and μ due to deformation. A change in the electron scattering mechanism below 110 K has been discovered.
Influence of plastic deformation on the photoconductivity of CdTe
Authors: Zozime A. , Schröter W. 
Published: July 2007

AbstractInvestigation of photoconductivity have been performed on p‐type phosphorus doped CdTe (5 × 1015 cm−3) deformed by compression at room temperature. Using a technique of axial illumination, the contribution of the surface to the photoconductivity is suppressed. In the investigated energy range (0.08–1.54 eV), and at room temperature, a maximum of the signal of the non‐deformed material is of found at 1.312 ± 0.009 eV, with a half width of 0.100 eV, whereas the 0.3% deformed material presents a maximum at 1.348 ± 0.009 eV with the same half width. At 223 K these peaks are shifted to higher energies, the half width remaining unchanged, and the amplitudes being ∼ 30 times higher.
Dislocation energy levels in deformed silicon
Authors: Patel J. R. , Kimerling L. C. 
Published: July 2007

AbstractAbstract‐Energy levels in deformed silicon have been directly measured by transient junction capacitance techniques. If complex slip band formation is not suppressed, a large variety of states are observed after deformation with a prominent state at Ev − 0.68 ev. After annealing at 900°C the complex defect spectra simplify to two dominant states at Ev + 0.35 ev and Ec − 0.38 ev. In more homogeneously deformed silicon where slip band formation is suppressed, the dominant state at Ec − 0.68 ev is not observed after deformation and the spectra resembles that obtained after annealing the complex spectra at 900°C.