bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of the Effective Vacancy Concentrations and the Vacancy Losses after the Quench of Al–Zn–Mg Alloys
Authors: Fabian H.‐G. , Wolter R. 
Published: January 2007

AbstractOn the basis of

the experimental observation of dislocation loops by means of TEM,
the conclusion from this that the concentration of vacancies in the dislocation loops exists at the cost of the vacancy concentration primarily present at Tq, and
the inversion of the decomposition kinetics of Al–Zn–Mg alloys found out by means of resistivity and microhardness measurements, the effective vacancy concentration cv.eff being at disposal for the GP‐zone formation was found out by means of the relation tR,max (tR,max being the time required to reach the maximum of resistivity) and the Arrhenius plot In tR,max = f(1/Tq) of the isothermal resistivity measurements. From the comparison of cv.eff with the theoretical V concentration at Tq it is possible to derive statements about the loss of vacancies during and after the quench through loop formation, building‐in of vacancies in GP‐zones and annealing of vacancies at lattice defects.From this comparison follows:

The ideal ZnV concentration at Tq (calculated by means of the Lomer equation) is sufficiently great to account for the effective vacancy concentration.
The part of cMgV in the loss concentration is rising with increasing cMg.
Both these statements support the hypothesis that the initial process of the decomposition in Al–Zn–Mg alloys is caused by the ZnV diffusion.
Determination of P, B, and Al Concentrations in Si by Photoluminescence (PL)
Authors: Schramm G. , Herzog R. , Kessler H. 
Published: January 2007

AbstractCalibration curves to determine P, B, and Al concentrations in silicon at 4.2 K from the intensity ratios of bound (BE) and free (FE) exciton related luminescence are presented. The integral relative intensities of the peaks are used besides the peak height ratios. By means of a large number of samples with widely varying concentrations it is shown that the influence of the compensation ratios of the samples on the determination of the dopant concentrations is smaller than the measurement errors. Integral intensity ratios of different BE phonon branches are also derived.
Investigations on the Synthesis of Zeolite ZSM‐5 (III)
Authors: Wilkosz J. , Stobiecka E. , Dudek B. 
Published: January 2007

AbstractThe effect of the chemical composition of the reacting mixture (RM) on the amount of zeolite ZSM‐5 and other crystalline phases and the amorphous phase as well in the obtained preparations was investigated. Ethylenediamine (ED) served as a templating agent. The quantitative estimation of the phase composition was made on the ground of X‐ray diffraction measurements. Zeolite ZSM‐5 of maximum phase purity of 96%, contaminated mainly with quartz and mordenite, was obtained.
Estimation of the Chemical Transport Behaviour of Transition Metal Silicides MeSix (Me = Cr, Ti, V, Mo, Fe, Mn) with X2 (X = Cl, Br, I)
Authors: Krausze R. , Krabbes G. , Khristov M. 
Published: January 2007

AbstractChemical vapour transport of transition metal silicides of Cr, Ti, V, Mo, Fe and Mn with halogen was estimated by a simple thermodynamic approach. The content of Si and Me in the gas phase is essential to the prediction of the transport. The dependence of the composition of the gas phase on the solid and the transport agent used is discussed and the results of the estimation are compared with experimental details.
RHEED Studies during Surface Cleaning of Silicon for MBE Substrates
Authors: Dominguez F. , Tempel A. , Zehe A. 
Published: January 2007

AbstractSilicon wafers were prepared for MBE growth by chemical treatment and temperature annealing under UHV conditions. The (7 × 7) and (2 × 1) reconstruction of {111} and {100}‐oriented Si surfaces were obtained only after high temperature annealing for few minutes at 1200 °C. The reconstruction effects were found to be stable for a long time even if the pressure in the UHV chamber increased to 10−5 Pa.
Growing of Optical Crystals Using a Propagating Temperature Field Technique
Authors: Lingart Yu. K. , Khazanov E. E. 
Published: January 2007

AbstractGiven hereby are the results of mathematical modelling of thermal conditions for the method of travelling temperature field (“travelling wave”). All the estimates have been made for the process of leucosapphire crystallization. Demonstrated are the advantages of the above method as against the horizontally directed crystallization on account of shifting the container.
Liquid‐Phase Epitaxy of (Hg, Cd)Te on CdTe Substrates by a Vertical Dipping Technique
Authors: Winkler M. , Teubner T. 
Published: January 2007

AbstractHg1−xCdxTe layers on CdTe substrates were grown from Te‐rich melt solutions by a vertical dipping technique using a special quasi‐closed system with ground‐glass sealing. Results are good reproducibilities of the electrical properties after annealing in Hg‐rich atmosphere (p77 ≈ 2 · 1016 cm−3 μ77 ≈ 500 cm2 V−1 s−1) and of the x‐value, respectively. A horizontal position of the substrate downwards to the melt solution yields, in difference to a vertical one, to homogeneous layer thicknesses. Short meltback steps before growth leads to sharper profiles of composition.
KRS‐5 Crystal Growth in Various Ambient Gases and Polycrystalline Fiber Preparation by an Extrusion Method
Authors: Hou Y. , Wang F. , Quan N. , Wang R. , Zhong H. 
Published: January 2007

AbstractKRS‐5 single crystals have been grown in three kinds of ambient gases: air, Ar, and Ar + I2. The scattering centers in crystals were inspected and the metal impurities and oxygen content of the crystals were analysed. The polycrystalline fibers with 0.5–1 mm in diameter have been prepared by an extrusion method. The stability and attenuation of the fiber are discussed.
The Influence of Mechanical Activation of Quartz and Quartz/γ‐Al2O3 Mixtures on the Sodium A Zeolite Formation
Authors: Wutzler R. , Klevzov D. , Steinike U. , Hennig H.‐P. 
Published: January 2007

AbstractIt could be shown that the preparation of sodium A zeolite is possible by the reaction of quartz and γ‐Al2O3 with NaOH‐solution. The zeolite formation is dependent on the mechanical preliminary treatment of quartz. Only the partially crystalline part of quartz dissolves and reacts with Al2O3 to form zeolite. The grinding of quartz/γ‐Al2O3 mixtures can in certain limits raise the zeolite formation but essentially only influences the kinetics of the zeolite formation.
Crystal and Molecular Structure of Bis(pyridine)N,N′‐o‐phenylen‐bis[2‐cyan‐2‐ethoxycarbonyl‐vinyl‐amido(–)]‐iron(II)‐Pyridine
Authors: Görls H. , Jäger E.‐G. 
Published: January 2007

AbstractThe crystal and molecular structure of bis(pyridine)N,N′‐o‐phenylen‐bis[2‐cyan‐2‐ethoxycarbonyl‐vinyl‐amido(–)]iron(II)‐pyridine were determined by X‐ray structure analysis. It crystallizes in the monoclinic space group P 21/c with cell parameters a = 9.866(23), b = 19.491(46), c = 16.992(22) Å, and β = 95.19(1)°. The structure was solved by the heavy atom method and refined to R = 0.125. The coordination geometry around the iron atom is octahedrally distorted with the two pyridine molecules in the axial positions.
Thermally Stimulated Luminescence of Montmorillonite Clay
Authors: Somaiah K. , Venkatanarayana M. , Sathyanarayana B. 
Published: January 2007

AbstractX‐ray excited luminescence (XL) spectra of montmorillonite clay at RT showed a broad emission band around 380 nm with two shoulders at 340, 450 nm eitherside two sharp peaks and two shoulders are seen at 465, 487, and 548, 576 nm, respectively. The 548 and 576 nm peaks enhanced their intensity at LNT. Whereas thermally stimulated luminescence (TSL) revealed an intense glow peak at 355 K and a weak shoulder around 400 K. Room temperature annealing studies indicated that the 355 K glow peak is not as stable as 400 K shoulder which turns out to be a peak on RT annealing. The X‐ray excited luminescence has been attributed to radiative recombination of electrons with holes which are associated with SiO3‐4, AlO4‐4 radicals and divalent impurities available in the naturally available clay. TSL is also understood on similar lines. Glow peak reactions are proposed tentatively and their trap parameters have been calculated.
Elastic Behaviour of Mn–Zn and Mg–Zn Ferrites
Authors: Showry K. , Murthy S. Ramana 
Published: January 2007

AbstractThe elastic moduli of four different composition of mixed Mn–Zn and Mg–Zn ferrites in the polycrystalline form have been measured at the room temperature using the ultrasonic pulse transmission method. The values of Young's modulus and the rigidity modulus are corrected to theoretical density using the method of Mackenzie. From the values of longitudinal and shear velocities, the Debye temperature has been calculated.
Temperature Dependence of Critical Sample Thickness for Spontaneous Cholesteric‐Nematic Phase Transition Between Surfaces with Homeotropic Anchoring
Authors: Pirkl S. 
Published: January 2007

AbstractTemperature dependence of the critical sample thickness at which a cholesteric structure unwinds spontaneously between surfaces with homeotropic anchoring are presented for some dielectrically negative chiral nematic mixtures. The results obtained are pertinent to the application of the nematic‐cholesteric phase change‐effect in liquid crystal devices.
Phase Transitions in n‐Pentadecanoic Acid: A Polarization Microscopy Study
Authors: Prasad P. B. V. 
Published: January 2007

AbstractA detailed polarization microscopy study is carried out to explore the nature of the heat induced phase transitions in n‐pentadecanoic acid. A′ (triclinic) → B′ (triclinic) and B′ (triclinic) and C′ (monoclinic) transitions are noticed to be fast and slow, respectively. It is understood that when the other influencing parameters (such as rate of heating) remain identical, in case of several transitions taking place in the same material, then the extent of stuctural difference between the mother and daughter phase is the transition rate determining factor.
Application of Modified Kick's Law to Rhombohedral Crystals: Calcite
Authors: Joshi D. R. , Pandya J. R. 
Published: January 2007

AbstractOptical study of mechanical response indicated by Knoop indentation of cleavage faces of natural rhombohedral clacite crystals based on MEYER'S law/KICK'S law (P adn) and also on modified KICK'S law (P–W) = bd2 is made. The response of cleavage faces for low load region (LLR) and high load region (HLR) of applied loads P to produce indentation mark of longer diagonal length is different. In LLR the Newtonian resistance pressure W is negative and varies with orientation and quenching temperature whereas in HLR it is positive and almost constant at room temperature and quenching temperatures. In LLR, W indicates crystal anisotropy. The values of resistance pressure W2 and standard hardness b2 in HLR are independent on thermal treatment and are constant within experimental limits. Since they are independent on indenter orientations, they are not associated with crystal anisotropy.
Infrared FTS‐Ellipsometry in the Investigation of Smectites
Authors: Hoeding T. 
Published: January 2007

AbstractThe paper presents IR spectra of montmorillonites and nontronites obtained with absorption measurements and FTS‐Ellipsometry. FTS‐Ellipsometry is a new method in the investigation of the vibration behaviour of clay minerals. The combination of these two IR methods enables the presentation of certain differences in the IR spectra of montmorillonites, also in the spectral region 1200 to 400 cm–1. Differentiations between special varieties and semiquantitative estimations (especially for iron) are possible.
Synthesis, Characterisation and Phase Transition Studies of 50.9 and 90.5
Authors: Pisipati V. G. K. M. , Rao N. V. S. , Reddy M. V. V. N. , Rao C. G. Rama , Padmavathi G. 
Published: January 2007

AbstractThe synthesis, characterisation of phases of the compounds N(p‐n‐pentyloxy benzylidene) p‐n‐nonylaniline, 50.9 and N(p‐n‐nonyloxy benzylidene) p‐n‐pentylaniline, 90.5 and phase transition studies using different experimental techniques are presented. The compound 50.9 exhibits a phase sequence NAB whereas 90.5 shows a phase variant ABG. A large density jump across IN transition is observed in 50.9 similar to that observed in 50.10 compound.
Characterization of a Trench Etching Process Using CBrF3 and Optimal Emission Spectroscopy of the Plasma
Authors: Wöhl G. , Haščik S. 
Published: January 2007

AbstractDry processes for deep silicon trench etching using CBrF3 were studied. The experiments were done in a single‐wafer reactive ion etcher in a low frequency and a high frequency mode. By optical emission spectroscopy of the CBrF3 plasma relative Br‐, F‐, CF3‐, and Br+ concentrations were measured as a function of applied frequency, pressure and power. Finally, in connection with d.c. bias voltage measurements some aspects of the etching mechanism are discussed.
Determination of Concentration of Rare Earth Ions Yb3+, Er3+, Tb3+, Ho3+, Tm3+ in Monocrystals of Yttriumaluminum Garnets on Basis of Magnetic Susceptibility
Authors: Dodokin A. P. , Kevorkov A. M. , Perlov D. D. , Sorokin A. A. 
Published: January 2007

AbstractCrystals of solid solutions (RxY1‐x)3Al5O12 (where R is rare earth ion Er3+, Yb3+, Tb3+, Ho3+, Tm3+) with garnet structure were grown. The temperature dependencies of magnetic susceptibility for these crystals were obtained. On the basis of measurement of magnetic susceptibility a non‐destructive technique for determining the concentration of rare earth ions in yttrium‐aluminum garnets was developed.
Some Possibilities for Investigation of the Energetics of Thin Ag Films on W
Authors: Michailov E. 
Published: January 2007

AbstractOn the grounds of adsorption‐desorption equilibrium measurements (ADE), by means of massspectrometer techniques (MS), a family Ag/W adsorption isotherms was obtained. The isotherms were analysed on the basis of a simple model, which allowed to reduce the well known equations of two‐dimensional (2D) state to an Arrhenius form, which was finally used to investigate the energetics of Ag–W and Ag–Ag interactions. The presence of real attractive Ag–Ag lateral interactions was established. The lateral binding energy per bond was estimated to be ∼ 0.065–0.088 eV/atom and ∼ 0.152 eV/atom for the first and second monolayers (ML), respectively.
Melt Growth of CdTe Crystals and Transmission Electron Microscopic Investigations of their Grain Boundaries
Authors: Sabinina I. V. , Gutakovski A. K. , Milenov T. I. , Lyakh N. N. , Sidorov Y. O. , Gospodinov M. M. 
Published: January 2007

AbstractTransmission electron microscopy investigations are carried out on CdTe crystals grown in quartz ampoules in a temperature region (1020–1091 °C) near to the melting point of 1092 °C, by travelling heater method in quasi‐closed and in sealed (at 0.135 Pa) volume, and by the Bridgman method from nearly stoichiometric melts. An original method for preparation of CdTe thin foil is reported. Two types of grain boundaries are observed: high‐angle misoriented grain boundaries (more than ten degrees misorientation between adjacent grains) and low‐angle misoriented grain boundaries (less than one degree misorientation between adjacent sub‐grain). Both dislocations with Burgers vector b = a/6 〈112〉 and b = a/2 〈110〉 are present.
Microinhomogeneities of Charge Carrier Concentration in GaAs
Authors: Kallenowsky T. , Koi H. , Boudriot H. , Oettel O. , Schneider H. A. 
Published: January 2007

AbstractThe tendency towards higher and higher integration of electronic components leads to increased requirements to the quality of the base material. The main requirement is homoneity of sturctural and related electronic and optoelectronic crystal properties of the base material within microscopic (and still decreasing) areas, in correspondence with the specific application.This paper is to present investigations of the correlation between local fluctuations of the charge carrier concentration and the occurrence of growth‐related striations in terms of IR absorption.
Growth Mechanism and Twinning of Sucrose Effected by Surface Adsorption Processes
Authors: Döhl B. , Follner H. 
Published: January 2007

AbstractGrowth experiments with sucrose dependent on temperature and supersaturation of solutions were carried out to find the conditions for appearance of the three different growth types. Measurements of growth rates of {110} and {110} faces at 50°C and supersaturation cs = 10% resulted in the known feature that in pure solutions a crystal grows faster in positive b‐direction than in the negative one. Addition of raffinose stopped growth of {110}. In an electric field generated by 20 kV direct voltage (crystal orientation: negative pole of b‐axis pointed towards the negative electric pole) the crystal grew in negative b‐direction three times faster than in the positive one. In the presence of raffinose the growth rates in both directions become equal. If the crystal is turned by 180° in the solution (pure solution and in the presence of raffinose) the growth behaviour is the same as without an electric field. These results can be interpreted in such way that in pure solutions sucrose molecules adsorb to {110} (bonds exist between the fructose rings of molecules in liquid and solid phases) and that in presence of raffinose these molecules adsorb to {110} (bonds exist between glucose (solid) and galactose rings (liquid phases)). By the electric field the adsorption is hindered. The theory is in accordance with the fact that crystals situated in a suspension of the solution can intergrow with a host crystal in twin positions (in pure solutions on {110} and in the presence of raffinose on {110}).
Semi‐Batch Precipitation of Calcium Oxalate Monohydrate
Authors: Millan A. , Grases F. , Söhnel O. , Křivánková I. 
Published: January 2007

AbstractCalcium oxalate monohydrate (COM) formation on the semi‐batch precipitation of CaCl2 and Na2C2O4 solutions in the stoichiometric ratio carried out at pH = 6 and 37 or 70°C, respectively, was studied. When a certain level of supersaturation in the system is reached, individual COM crystals of a rather uniform size are formed. These crystals then grown and form ‘loose’ agglomerates that later develop into compact and spherical particles. The particle size distribution (PSD) rapidly shifts during early stages of precipitation towards larger sizes as a result of crystal growth and agglomeration. Later the PSD reaches a shape and position on the size axis that remain virtually constant with progressing precipitation. COM agglomerates consisting of mainly intergrown crystals are formed by mechanism of primary and secondary agglomeration. The primary agglomeration can constitute an important factor in urolithiasis.
Structure of Polycrystalline Cu Films as Solar Selective Coatings
Authors: Ramadan A. A. , Abdel‐Raheem S. K. , El‐Shabiny A. M. , Kaid M. F. 
Published: January 2007

AbstractCopper thin films (5–150 nm) were prepared by vacuum deposition with different rates (0.7, 1.5 and 3 nm/s). The position, intensity and profile of X‐ray diffraction lines were analysed to study the phases, the crystallographic preferred orientation as well as the residual strain and crystallite size. The fcc polycrystalline Cu phase was revealed and no oxide phases were identified. The films were highly oriented with 〈111〉 fiber texture. The ratio of P111/P200 increased with the film thickness. Thus, in case of amorphous substrate, the type of the crystallographic texture of a film depends mainly on the structure of the deposited material. The crystallite size increases while the residual strain decreases, as the film thickness or the deposition rate is increased. The crystallite size was very small compared with the film thickness. The effect of deposition rate was pronounced specially from 0.7 to 1.5 nm/s.
Structure‐Property Investigation of TAMP, TAMS, and TAMM Crystals
Authors: Genbo Prof. Su , Jiangxian Wu , Feng Pan , Youping He , Zhengdong Li , Qingzhen Huang , Jingkui Liang 
Published: January 2007

AbstractThe thermal properties, the powder second‐harmonicgeneration (SHG) signal and some electrical properties of the TAM‐tetraoxygen‐acid‐salts, e.g., (HOH2C)3CNH3 · H2PO4 (TAMP), ((HOH2C)3 · CNH3)2SO4 (TAMS) and (HOH2C)3CNH3 · NH4 · MoO4 (TAMM), are reported. TAMP and TAMM are established to be useful nonlinear optical materials.
Crystal Structure Determination of Nickel (2,2‐Dipyridyl) Sulphate Hexahydrate [Ni(C10H8N2) · 4 H2O]SO4 · 2H2O
Authors: Farag I. S. Ahmed , Gad A. A. M. , Awadallah R. M. 
Published: January 2007

Abstract[Ni(C10H8N2) · 4 H2O]SO4 · 2 H2O, Mr = 418.7, monoclinic, P1, a = 7.781(3), b = 9.421(3), c = 11.457(4) Å, α = 87.54(2)º, β = 96.40(2)º, γ = 102.58(2)º, ν = 814.5 Å, Dx = 1.26 g/cm3, Z = 2, (MoKx) = 0.71073 Å, μ = 7.0 cm−1: T = 23 °C, R = 0.047 for 2139 reflections having intensities greater than 36. The structure was solved using the Patterson heavy‐atom method and the remaining atoms were located in succeeding difference Fourier syntheses. The structure was then refined by full matrix least‐squares using anisotropic temperature factors. Hydrogen atoms were located and their positions and isotropic parameters were refined.
The Crystal and Molecular Structure of 1α,2α‐Methylene Gibberellin A3 Methyl Ester
Authors: Kutschabsky L. , Kretschmer R.‐G. , Voigt B. , Adam G. 
Published: January 2007

AbstractThe three‐dimensional structure of the 1α,2α‐methylene gibberellin A3 methyl ester has been determined by single‐crystal X‐ray diffraction techniques. The crystals are monoclinic, space group P 21 with two molecules in the unit cell of dimensions a = 9.236, b = 7.109, c = 14.155 Å and β = 104.61º. The structure was refined to an R‐value of 0.0983 for 1359 observed reflections.
Evaporation Behaviour of TMIn‐TMN Adduct Determined by flame Ionization Detection
Authors: Hagen S. , Seifert W. , Butter E. 
Published: January 2007

AbstractAs the first time the evaporation behaviour of trimethylindium‐trimethylamine (TMIn‐TMN) was investigated with a flame ionisation method. Individual metalorganic components can be detected in rather low concentrations (10−2 Torr) in a hydrogen carrier gas. A reproducible and constant supply could be realised with the solid TMIn‐TMN‐adduct in accordance with the equation for the vapour pressure: Ig p = −2597 · T−1 + 8.748 (p in Torr) in the temperature range 273 K < T < 294 K. 99% of the steady state value of TMIn‐TMN concentrations in hydrogen was reached within 5–7 min after switching the bubbler into the gasstream.
The Formation of NiZn Ferrite from Mixed Hydroxides
Authors: Fischer S. , Töpelmann W. , Scheler H. , Michalk C. , Knese K. 
Published: January 2007

AbstractThe formation of Ni0.5Zn0.5Fe2O4 from mixed hydroxides was investigated by XRD, Mössbauer spectroscopy and magnetic measurement. For the synthesis of the ferrites mentioned not only the hydroxides Ni(OH)2, Zn(OH)2, FeOOH precipitated under defined conditions were used but also a mixture of ZnFe2O4 (obtained by coprecipitation) with aliquout Ni(OH)2 and FeOOH quantitites, aged in aqueous environment. Subsequently, the powders isolated are tempered. The mixed ferrite Ni0.5Zn0.5Fe2O4 is directly formed from the hydroxide products without other oxidic phases being detectable. But no homogeneous distribution of Ni2+ − or Zn2+ −ions in the spinel is obtainable even after tempering at 500 °C. On the contrary, the mixed ferrites arises only to a small extent from the ZnFe2O4, Ni(OH)2 and FeOOH mixture. Mainly, NiO and α‐Fe2O3 are formed. The dependence of processes is discussed in the mixed ferrite phase formation on synthesis, ageing and tempering conditions.