bluuebunny/crossref_metadata_2025_split huggingface dataset:
Precipitation and dissolution of KCaCl3 impurity in NaCl crystals
Authors: Andreev G. A. , Buritskova L. G. , Hartmanová M. 
Published: July 2007

AbstractImpurity precipitation in NaCl crystals containing CaCl2 and KCl in various proportions is studied by means of flotation density measurements. The paper is concerned with the determination and dissolution, the kinetics and activation energy, and the mechanism of nucleation. Two temperature regions for solid solution decomposition were revealed. The characteristic stages in density variation upon isochronal annealing are shown to be correlated with radical changes in the X‐ray diffraction patterns. Evidence is given that the nucleation is heterogeneous for the stable phase and homogeneous for the metastable one. – The activation energy in the low‐temperature region has been found to be 0.8 ± 0.1 eV, which suggests precipitation to be diffusion‐limited. From the kinetics studies it follows that the composition of the metastable phase corresponds to KCaCl3 and the rate‐controlling stage in stoichiometric crystals is a K+ diffusion.
Der Einfluß der Stapelfehlerenergie und der Atomgröße‐Schubmodul‐Differenzen auf Versetzungsstruktur und ZSD ermüdeter kfz‐Metallegierungen
Authors: Blochwitz C. , Mecke K. , Stephan R. 
Published: July 2007

AbstractDie zyklische Spannungs‐Dehnungs‐Kurve von NiFe‐ und NiCo‐Legierungen hängt von der zyklischen Verformungsvorgeschichte ab. Unterschiedliche Versetzungsgrobkonfigurationen (einphasen‐ oder zweiphasenähnliche Struktur) sind die Hauptursache dieses Verhaltens. Geringe Stapelfehlerenergie (NiCo) und große Atomgröße‐Schubmodul‐Wechselwirkung (NiFe) beeinflussen die Versetzungsstruktur in der gleichen Weise.
Die Temperaturabhängigkeit des Dotanteneinbaus bei der Abscheidung von Siliziumepitaxieschichten aus der Gasphase (I) Der Phosphoreinbau und die Natur des Segregationskoeffizienten
Authors: Kühne H. 
Published: July 2007

AbstractAusgehend von der Anwendung des Henry‐Gesetzes N = (P)1/i · 1/Hi auf die Partialdrucke der einzelnen, im Dampfgleichgewicht des elementaren Phosphors vorhandenen Molekülarten wird der Segregationskoeffizient von Phosphor zwischen Gasphase und wachsender Siliziumepitaxieschicht (kSegr.; P) mit der reziproken effektiven Henry‐Konstante (1/Hi*) identifiziert. Damit wird der Einbau von ionisierten Phosphoratomen in die Silziumschicht als elementarer Prozeß angesehen. Der Segregationskoeffizient ist nicht nur von der Temperatur, sondern auch von der Phosphordampfzusammensetzung und damit von der Dotanteneinbaukonzentration abhängig.
Chemistry of organic eutectics (III). α‐Naphthol‐naphthalene system
Authors: Singh N. B. , Rastogi P. , Singh Narsingh Bahadur 
Published: July 2007

AbstractRelative supercooling, linear velocity of crystallization and microstructure for the α‐naphthol‐naphthalene eutectic system have been investigated in order to understand the mechanism of eutectic solidification. Heat of fusion measurements indicate the possibility of molecular association in the liquid melt. The effective distribution coefficient, direction of solute transference, and separation efficiency have also been determined using zone melting technique.
Beitrag zur Kenntnis der Beziehungen zwischen Aktivierungsmechanismus und Strukturänderungen in Festkörpern Untersuchungen zur Verteilung amorpher Bereiche auf schwinggemahlenen Quarzoberflächen
Authors: Steinike U. , Ebert I. , Jedamzik J. , Kretzschmar U. , Hennig H.‐P. 
Published: July 2007

AbstractEs wurden die Dicken röntgenamorpher Schichten nach verschiedenen Methoden abgeschätzt und mit Literaturwerten verglichen. Die mittlere Schichtdicke liegt zwischen 10 bis 30 nm und ist weitgehend unabhängig von der erreichten Amorphisierung und der spezifischen Oberfläche. Ein Modell der Verteilung der röntgenamorphen Bereiche um das Quarzkorn wird vorgestellt.
Die Züchtung von Pb1−xSnxTe‐Einkristallen mit vorgegebenem Zusammensetzungsgradienten mit Hilfe einer wandernden Lösungsmittelzone
Authors: Link R. , Nötzel N. , Ermisch W. 
Published: July 2007

AbstractDurch entsprechende Wahl der Zusammensetzung der Lösungsmittelzone, des Quellkristalls und des Substratkristalls lassen sich mit Hilfe einer im Temperaturgradienten wandernden Lösungsmittelzone (Travelling Solvent Method, TSM) etwa 0,5 mm dicke Pb1−xSnxTe‐Einkristallscheiben mit variierendem x herstellen. Die aus Untersuchungen an einer Elektronenstrahl‐Mikrosonde ermittelte Zusammensetzung der Kristalle wird mit Hilfe einer elementaren Theorie beschrieben. Es werden Angaben über die Zinnsegregation bei der Züchtungstemperatur 585 °C gemacht.
Etching behaviour to MgO crystals in relation to chemical reactions
Authors: Sangwal K. , Patel T. C. 
Published: July 2007

AbstractExperimental results of an investigation of the etching behaviour of {100} faces of MgO crystals under different etching conditions in acids, alkalies and inorganic salts are presented. It is observed that etching takes place in aqueous solutions of acids and acidic salts and in the melts of NaOH and KOH. On the basis of an analysis of the results it is suggested that the energetics of chemical reactions dictate the choice of etchants for a crystal.
Electron probe microanalysis of CuInSe2 and CuGaSe2 crystals
Authors: Möller W. , Kühn G. , Beier W. 
Published: July 2007

AbstractA correction procedure for the quantitative electron probe microanalysis of nonstoichiometric crystals in the system CuInSe2–CuGaSe2 is presented and applied to the analysis of the terminal members of the mixtures. In CuInSe2 samples a precipitation of Cu2Se takes place due to an evaporation of volatile compounds with a composition ratio In: Se = 2:3. A similar reaction was observed in the case of CuGaSe2.
XPS‐study of the interaction of air‐oxygen with platinum surfaces
Authors: Wagner N. , Brümmer O. 
Published: July 2007

AbstractThe differences in the XPS spectra of the band regions Pt4f, Ols and VB between cleaned and air exposed polycrystalline platinum samples are discussed. After defined exposure it appears PtOads. and a cation configuration of 5d8 6s1 for platinum. This can be shown by line shapes, especially by the double peak structure of oxygen lines and by the asymmetrical tail on the high binding energy region of Pt4f combined with valence band results.
Crystal and molecular structure of the phenyl‐trimethine‐merocyanine C9ONH9
Authors: Kulpe S. , Schulz B. 
Published: July 2007

AbstractThe phenyl‐trimethin‐merocyanine crystallizes in the space group I 4 with 8 molecules per unit cell. The lattice constants are a = b = 16.121 Å, c = 6.549 Å, α = β = γ = 90°. The intensities were measured with an automatic single crystal diffractometer. The solution of the structure was obtained by applying the convolution molecule method and the R‐value method. The refinement was performed by least‐squares blockdiagonal method to an R‐value of 7.2% for 1067 independent reflexions. The C–C‐bond lengths within the plane of the trimethin chain alternate as in the molecule structure of the morpholylpentamethine‐merocyanine and thus point to a distinct polyenic behaviour. The valence angles within the chain alternate as well. This property indicates a polymethinic behaviour of the molecule. The geometry of the molecule proves the merocyanines to have an intermediate position between the polymethinic and the polyenic state. For a more detailed discussion we refer to the discussion of the morpholyl‐pentamethine‐merocyanine structure.
The investigation of solid state reactions taking place in the AlZn (4.5 at.%)–Mg (2;3 at.%) alloys by interrupted continuous heating
Authors: Sackewitz K.‐H. , Radomsky M. , Löffler H. , Kabisch O. , Ungár T. , Honyek G. , Lendvai J. , Kovács I. 
Published: July 2007

AbstractThe decomposition and dissolution processes taking place in these alloys during continuous heating interrupted at certain temperatures, cooled quickly to RT and heated again are followed by means of TEM, XSAS, resistivity, DTA, and DSC measurements. It could be stated that during these heat treatments the decomposition sequence GP zones η′ happened. The presence of X‐phase could not be pointed out surely.The GP zones formed at lower temperatures are dissolved partially before the formation and growth of η′‐particles takes place. Indications were found that the presence of η′‐particles in the matrix makes the η′‐precipitates instable in the neighbourhood of the η′‐particles.
Ein Beitrag zur Entstehung von Spannungen und Versetzungen beim Kristallwachstum
Authors: Indenbom V. L. 
Published: July 2007

AbstractAn Hand charakteristischer Beispiele werden halbquantitative und quantitative Methoden zur Abschätzung bzw. Berechnung und Analyse von thermoelastischen Spannungen bei der Kristallzüchtung aus der Schmelze erläutert. Die Spezifik der Bildung thermoplastischer Spannungen in Kristallen mit unterschiedlichen rheologischen Charakteristiken wird betrachtet. Möglichkeiten zur Abschätzung der Versetzungsdichte und ihrer Verteilung im Kristall aus dem axialen Temperaturgradienten, der Größe und Verteilung der thermoelastischen Spannungen und dem Zustand der Spannungsrelaxation werden diskutiert.
Growth kinetics, morphology, and electrical properties of nGaAsnGaN heterojunctions
Authors: Šrobár F. , Procházková O. , Kohout J. , Zelinka J. , Šimeček A. 
Published: July 2007

AbstractnGaAsnGaN heterojunctions were fabricated by one‐stage conversion of monocrystalline GaAs under varying conditions. Surface and cross section study, performed by means of optical and electron microscopy, indicates that the growth kinetics is essentially controlled by transfer of ammonia molecules across the already grown nitride layer; the diffusion coefficient value at 700°C being 3.1 × 10−10 cm2 sec−1. Current‐voltage behaviour, describable by relations of the type I = I0(T) exp (αV), appears to be dominated by tunneling processes.
Einige Erfahrungen mit dem Wachstum von LiTaO3‐Einkristallen
Authors: Šimáček V. , Tůma P. 
Published: July 2007

AbstractEinkristalle von LiTaO3 wurden nach der Czochralski‐Methode aus Pt‐Tiegeln gezogen. Sie wurden zur Herstellung von Lichtleitern durch Eindiffundieren von Nb verwendet.
On the coexistence of phases at the α–β transition in quartz
Authors: Semenchenko V. K. , Bodnar I. T. , Fotchenkov A. A. 
Published: July 2007

AbstractThe character of the α–β transition in crystals of natural and synthetic quartz has been studied by measuring the refractive index. The coexistence of two different crystallographic modifications over some temperature range has been established. The α–β phase transition is supposed to be attributed to the near‐critical phase transitions. In synthetic quartz with Al and Fe structural impurity the α–β transition consists of two successive transitions. First the transition from the α‐phase to an intermediate one takes place, then the intermediate phase is transformed into the β‐Phase. Within a certain temperature range there exists only the intermediate phase.
Induction period of the calcium nitrate‐water system
Authors: Pacák P. , Horsák I. , Sláma I. 
Published: July 2007

AbstractThe induction period‐supercooling dependence was measured in calcium nitrate‐water system within the concentration range 1.5–23 mol% of Ca(II). It was found that the behaviour of the system may be described by the equations for transformation kinetics with the use of classical theory of homogeneous nucleation in glasses. From the experimental data values of interfacial tension of the liquid‐solid interface were calculated and correlated qualitatively with the observed stability of the studied system with respect to crystallization.
Change in morphology and dislocation Etch Pits on the (010) Surface of Magnesium Orthosilicate Crystals
Authors: Desai C. C. , John V. 
Published: July 2007

AbstractInvestigations made on the etching behaviour of magnesium orthosilicate crystals in hydrochloric acid and melts of potassium and sodium hydroxides are described. It is shown that the morphology and orientation of the etch pits depend upon the concentration, composition and temperature of the etchant used. At low concentrations of HCl acid solution, the boat shaped pits produced are oriented along [100] direction while in concentrated acid, the hexagonal pits produced are oriented along [001] direction. At intermediate concentrations of about 5 N HCl acid the pits are square. KOH melt at 400 °C is found to produce rectangular pits with their longer sides parallel to [100] direction. The effect of a mixture of KOH and NaOH in different proportions in the melt is investigated. It is observed that square pits are obtained in melt of the mixture of KOH and NaOH in the proportion of 6:4 respectively. The mechanism responsible for the change in orientation of etch pits have been explained. The implications are discussed.
Influence of Chromium and Titanium Oxide Dopants on the Real Structure and the Mechanical Properties of Corundum Single Crystals
Authors: Gościńska T. , Auleytner J. 
Published: July 2007

AbstractThe real structure and the mechanical properties of pure and doped corundum single crystals have been investigated. The single crystals were obtained by the Verneuil‐method. The results allow to propose two different models concerning the influence of the chromium and titanium oxide on the properties of corundum single crystals.Optimum concentration of the chromium oxide impurities was approximately determined, from which corundum single crystals with higher hardness can be obtained. It was stated that titanium oxide impurities with some concentrations made the crystals more fragile without plastically changes in the region of the individual mosaic blocks.
Zur Bestimmung des Zerstäubungskoeffizienten bei der Ionenätzung
Authors: Mamaev G. I. , Seidowski E. , Ledovskoj V. P. 
Published: July 2007

AbstractDie Berechnung des Wechselwirkungsquerschnitts bei der Ionenzerstäubung unter Anwendung einer allgemeinen Formel für die Streuung geladener Teilchen, die für beliebige Winkel gilt, erlaubt in Verbindung mit der Nikulin'schen Abschirmfunktion eine genauere Bestimmung des Zerstäubungskoeffizienten nach dem Kaskadenmodell. Die erhaltenen Werte befinden sich in guter Übereinstimmung mit dem Experiment.
The Molecular and Crystal Structure of p‐methyl‐phenyl‐glyoxyacid‐p‐chloranilide
Authors: Höhne E. , Seidel I. 
Published: July 2007

AbstractUsing X‐ray crystal structure analysis of the title compound the positions of all the atoms (including all H atoms) in the monoclinic unit cell with the parameters a = 13.900 Å, b = 5.138 Å, c = 17.956 Å and β = 91.05° and the space group P 21/n were localized. The existence of an intramolecular N—H(N)…︁ O(1)‐bridge was inferred, whose H‐bridge acceptor predominantly is the π‐electron density of the carbonyl group. At the same time the H(N) atom participates in the intermolecular bridge NH(N)…︁ O′(1) to the symmetry‐equivalent neighbouring molecule. H‐bridge‐like interactions of the two phenyl hydrogen atoms H(6) and H(15) to the carbonyl oxygen O(2) have also been inferred from the torsion angles.
Structural Properties of S‐alkylated Dithiolene Chelates (I). Crystal and Molecular Structures of Bis(S‐ethyl‐ethene‐1,2‐ dithiolato)palladium (II) and Bis(S‐ethyl‐ethene‐1,2‐dithiolato) platinum (II)
Authors: Sieler J. , Richter R. , Kaiser J. , Kolbe R. 
Published: July 2007

AbstractBis(S‐ethyl‐ethene‐1,2‐dithiolato)palladium(II), Pd(S2C4H7)2, is monoclinic, P 21/n, with a = 7.598(1) Å, b = 10.445(2) Å, c = 8.031(1) Å, β = 95.3(1)° and Z = 2. The structure was determined by 893 independent reflections and refined by the block‐diagonal leastsquares method to R = 0.12. The chelate molecule is nearly planar and the palladiumsulfur distances are 2.278(6) Å and 2.403(6) Å.Bis(S‐ethyl‐ethene‐1,2‐dithiolato)platinum(II), Pt(S2C4H7)2, is monoclinic, P 21/a, with a 13.114(2) Å, b = 12.873(2) Å, c = 7.446(2) Å, β = 96.1(1)° and Z = 4. The structure was solved from 2040 independent reflections. The compound is not isomorphic with the isomeric palladium complex. In the unit cell there exist two symmetry independent molecules. The platinum‐sulfur distance is 2.280 (6) Å.
Dynamic Aspects of Dislocation Behaviour Near Low‐Angle Boundary in Molybdenum Single Crystals
Authors: Novikov I. I. , Kantor M. M. , Yermishkin V. A. , Plastini V. M. , Timofeev V. N. 
Published: July 2007

AbstractThe dislocation behaviour was inventigated in specimens of monocrystals of molybdenium during in — situ stretching in the direction [001] near low — angle twist boundary which was close to be parallel to the direction of the external force. Low‐angle boundary is easily penetrable for the fast moving nonscrew dislocations and acts as an effective stopper for screw dislocations which are quite parallel to the forming boundary dislocations. The mixed tipe dislocations emission by the low‐angle boundary was noticed. On the stage when plastic deformation is performed mainly by the motion of screw dislocations the “relay‐race”‐like transmission of the dislocations motion through the boundary was observed.
Plastic Deformation of BCC Metals — Open Problems
Authors: Šesták B. 
Published: July 2007

AbstractFor a deeper understanding of the plastic behaviour of bcc metals a detailed knowledge of the mobility of screw dislocations, which is intimately connected with their core structure, is necessary. A critical review of our present knowledge indicates an almost absolute lack of quantitative information on screw dislocation mobility at finite temperatures. Therefore, a detailed experimental and theoretical study of these processes is an open problem of great importance. Such a study would be of great value for the entire field of plastic deformation of bcc metals.
HVEM In‐situ Deformation Investigations on Cyclically Deformed Nickel Single Crystal
Authors: Mecke K. , Messerschmidt U. 
Published: July 2007

AbstractIn‐situ deformation investigations were carried out on thin foils of a nickel single crystal which was cyclically pre‐deformed. The motion of dislocations does not start in the whole specimen simultaneously but begins at localized places in the dislocation‐poor regions. The plastic deformation may be characterized by a collective movement of dislocations. Measurements of the effective stress show its characteristic dependence on the position in the direction of the Burgers vector. There are clear indications of structural changes in the dense regions of dislocations at strains exceeding the cyclic total strain amplitude.
Method of Evaluating Geometrical‐Statistical Parameters of the Interaction between Dislocations and Point Obstacles from Electron Micrographs
Authors: Messerschmidt U. , Appel F. 
Published: July 2007

AbstractElectron micrographs of MgO crystals deformed in the HVEM show screw dislocations of curly shape. The dislocations are pinned at localized obstacles and bow out between them. The paper describes a measuring procedure for the geometrical interaction parameters between the dislocations and the obstacles. Such are the effective stress, the obstacle distance and the force acting on the obstacles. The procedure consists in a graphical fit of loops calculated by the DE WITT‐KOEHLER line tension model to the observed dislocation segments.
Crystal and Molekular Structure of Piperidinium‐acet‐p‐Cl‐anilide‐chloride
Authors: Reck G. , Bannier Gloria 
Published: July 2007

AbstractPiperidinium‐acet‐p‐Cl‐anilide‐chloride crystallizes in the triclinic space group P 1 with 2 formula units C13H18ON2Cl2 in the unit cell. The lattice constants are a = 10.471 Å, b = 12.545 Å, c = 6.149 Å, α = 72.14°, β = 105.70° and γ = 105.21°. Bond lengths, bond angles and the conformational flexibility were determined by X‐ray structure analysis. The crystal structure contains dimeres consisting of drug molecules connected by hydrogen bonds.
The Crystal Structure of 3‐Methoxy‐estra‐1,3,5(10)triene‐16αBr,17αOH
Authors: Szulzewsky K. 
Published: July 2007

AbstractThe steroid 3‐Methoxy‐estra‐1,3,5(10)triene‐16αBr,17αOH crystallizes in the orthorhombic space group P 212121 with lattice constants a = 30.653(5) Å, b = 9.039(2) Å, c = 6.098(1) Å. The single molecule has an intramolecular OH…︁ Br interaction. Intermolecular interactions are only of van der Waals type. Ring A is nearly planar, ring B has a nearly half chair conformation, ring C has a chair conformation and ring D an envelope conformation.
The Diffusion Influence in Melt on the Solid Solution Formation for a System of Eutectic Type
Authors: Cherepanova T. A. , Didrihsons G. T. 
Published: July 2007

AbstractOn the example of a model eutectic system an investigation was carried out on the crystallization regularities taking into account diffusion mass transfer to the interface under diffusion and kinetic growth regimes. The authors bring forward a possible mechanism of formation of continuous series of supersaturated solid solutions under speedy hardening from a liquid phase. The shape of kinetic phase diagrams was found.
α‐substituted phosphoryl compounds (III). The crystal and molecular structure of diphenyl[1,3‐benzodithiolyl‐(2)]‐phosphinoxide, C19H15OPS2
Authors: Kulpe S. , Seidel I. 
Published: July 2007

AbstractDiphenyl[1,3‐benzodithiolyl‐(2)]‐phosphinoxide crystallizes in the monoclinic space group P 21/c with four molecules per unit cell. The lattice parameters are a = 9.600 Å, b = 11.270 Å, c = 16.484 Å; β = 99.72°. With X‐ray diffraction data collected at an automatic four circle diffractometer, the crystal structure has been solved by direct methods and refined to an R‐value of 0.08 for 2690 measured and symmetrically independent reflections. The substance is a derivative of acetales of formyl diphenyl phosphine oxides. Correlations between the geometry of the structure and NMR‐data are of interest.
On the reproducibility of the orientation distribution function of texture samples from pole figures (I). Relationship between the odf and pole figures
Authors: Matthies S. 
Published: July 2007

AbstractThe explicit relationship between the orientation distribution function and the pole figures measured by means of diffraction experiments is derived and discussed. It is shown that these pole figures have a higher symmetry than the ODF, i.e. that it is impossible to reproduce unambiguously the ODF from pole figure datas only. From this circumstance follows that the ODF reproduced by help of usual methods are falsified and contain ghost phenomenas.
Strength investigations of subsurface regions stressed by tribomechanical loading
Authors: Kampf S. , Schilling A. , Solondz D. , Wuttke W. 
Published: July 2007

AbstractPolycrystalline copper and monocrystalline iron were tribomechanically loaded in a defined way. By fundamentals of a continuum mechanical analysis of the stress field and a transmission electron microscopical investigation of the dislocation arrangement conclusions were made regarding the crack nucleation, the crack propagation and the wear resistance. The proved development of a dislocation cell structure is an adaptation of the material to the friction loading to tolerate a high number of loading cycles without wear.
Electric conductivity and lattice disorder of PbMoO4 crystals
Authors: Bollmann W. 
Published: July 2007

AbstractFrom differential thermal analysis (DTA), thermal etching, perfectly reversable redox treatments and electric conductivity it is concluded that the Pb/Mo ratio of the PbMoO4 crystals is always 1 and that phase transitions do not occur. Pb3+ ions detectable by an absorption band at 435 nm cause a p‐conductivity due to the reaction Pb3+ ⇌ Pb++ + e+. At elevated temperatures the p‐conductivity increases with increasing oxygen partial pressure of the surrounding atmosphere. The influence of foreign ions on the concentration of ionic and electronic defects in PbMoO4, CaMoO4, PbO, and PbTiO3 can be explained by an anti‐Frenkel disorder of the oxygen ion sublattice. For PbMoO4 crystals the mobility O− ion vacancies and the free formation enthalpy of anti‐Frenkel defects are found to be vv = \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop - \limits_T^{9160} $\end{document} exp (−1.15 eV/kT) cm2 K/Vs and gAF = 3.6kT −2.2 eV, respectively.