bluuebunny/crossref_metadata_2025_split huggingface dataset:
The growth of high‐quality MCT films by MBE using in‐situ ellipsometry
Authors: Svitashev K. K. , Dvoretsky S. A. , Sidorov Yu. G. , Shvets V. A. , Mardezhov A. S. , Nis I. E. , Varavin V. S. , Liberman V. , Remesnik V. G. 
Published: January 2007

AbstractThe ellipsometry and RHEED study of high‐quality MCT films grown on (112)‐ and (130) CdTe and GaAs by MBE was carried out. The dependence of the ellipsometric parameter ψ on MCT composition is evaluated. It was shown that such parameters as growth rate, the surface roughness, initial substrate temperature, and film composition may be measured by the in‐situ ellipsometry. The appearance of surface roughness was observed in the initial stage of MCT growth under various compositions (xCdTe = 0 ÷ 0.4). The further growth at optimum conditions leads to the smoothing of the surface and supplies us with high‐quality MCT films. The concentration, mobility, and life time of carriers in MCT films were respectively: n = 1.8 × 1014 ÷ 8.2 × 1015 cm−3, μn = 44000 ÷ 370000 cm2 V−1 s−1, τn = 40 ÷ 220 ns; p = 1.8 × 1015 ÷ 8.4 × 1015 cm−3, μp = 215 ÷ 284 cm2 V−1 s−1, τp = 12 ÷ 20 ns.
Defect studies in CuBIIIC chalcopyrite compounds using the ion channeling technique
Authors: Neumann H. 
Published: January 2007

AbstractBased on simple approximations the backscattering minimum yield is estimated for axial ion channeling in perfect crystals of six CuBIIICchalcopyrite compounds. The results obtained for CuInSe2are compared with experimental channeling spectra. Point defect concentrations up to about 1021cm−3are estimated for CuInSe2single crystals grown by the vertical Bridgman method. A simple power law is found for the fluence dependence of the damage density in oxygen implanted CuInSe2single crystals.
Characterization of dislocations in a LiNbO3 single crystal grown by micro pulling down method
Authors: Yoon D. H. , Yonenaga I. , Fukuda T. 
Published: January 2007

AbstractLiNbO3 single crystals grown by the micro pulling down (μ‐PD) method have been revealed to be as free of dislocations and subgrain boundaries up to 500 μm in diameter. On the other hand, μ‐PD LiNbO3 single crystals grown along the x‐axis in diameter of 800 μm were observed to be dislocated due to the size effect of crystal. The Burgers vectors of dislocations were determined to be [2201], [1011], and [0111] by X‐ray topography.
Li–Zn ferrites with nonmagnetic additives
Authors: Rezlescu N. , Rezlescu E. , Craus M. L. , Pasnicu C. 
Published: January 2007

AbstractThe authors investigated the effect of small additive amounts of non‐magnetic ions as Na1+, Ca2+, Zr2+, Sb3+ and binary or ternary combinations of these ions on some physical properties of the (Li0.5Fe0.5)0.6Zn0.4Fe2O4 ferrite used in high frequency. It was found that by the segregation of these additives on the grain boundaries, the grain growth is diminished and much higher sintered densities are obtained in several cases, though not all. We established that additives such as Na2O, CaO, ZrO2 enhance the rate of sintering, giving a speedy start to the sintering process. All additives improve the electrical resistivity due to insulating intergranular layers generated by segregation of additives.
Growth of corundum single crystals by the top‐seeded solution growth technique (TSSG)
Authors: Watanabe Koichi 
Published: January 2007

AbstractSingle crystals of corundum were grown by the top‐seeded solution growth technique from a cryolite, Na3AlF6, solvent. The relationship between the growth rate (mg/h) of a crystal and the temperature difference (= supersaturation) or the rotation rate of a seed crystal was investigated, and optimum growth conditions for obtaining single crystals with good quality are discussed.
Crystal structure of a dehydroabietate derivative
Authors: Padha Naresh , Singh Vinod , Subramaniun E. , Gupta K. K. , Taneja S. C. , Goswami K. N. 
Published: January 2007

AbstractThe crystal structure of methyl‐16, nor‐5‐hydroxy‐6,7,15‐trioxo dehydroabietate has been determined from three‐dimensional X‐ray diffraction data. The compound crystallizes in the orthorhombic space group P21212 with unit cell parameters a = 19.226(3) Å, b = 11.075(3) Å, c = 8.375(2) Å, Z = 4, V = 1783.3(7) Å3, d0 = 1.36 gcm−3. The gross structure was determined by direct methods which on refinement yielded a final value of R index as 0.038. Ring A is a chair, ring B an envelope whereas the ring C adopts a strictly planar conformation. The rings A and B are trans fused. The ester group at C4 is cis fused to methyl carbon C15 whereas another methyl carbon C18 and oxo O(15) of the isopropyl group at C13 are rotated to positions 0.107(3) Å and 0.179(2) Å out of the plane of ring C.
Crystal and molecular structure of the chiral compound 4–(2–methylbutyloxy)phenyl–4–(2‐propenyloxy)‐benzoate, C21H24O4
Authors: Kaeding A. , Zugenmaier P. 
Published: January 2007

AbstractThe enantiomeric [(S)‐(–)‐MBP3B] and the racemic form [(±)‐MBP3B] of the title compound with the formula C3H5O–C6H4–CO2–C6H4–OC5H11were studied by single crystal analysis at room temperature.(S)‐(–)‐MBP3B crystallizes in the orthorhombic space group P212121witha= 7.835(3) Å,b= 11.093(6) Å,c= 44.820(3) Å and 8 molecules per unit cell. The structure was determined from 966 reflections with intensities > 3σ. The refinement with isotropic temperature factors leads toR= 0.094.The crystals of the racemic form are monoclinic, space group P21/a witha= 7.899(5) Å,b= 11.046(6) Å,c= 22.845(12) Å, β = 99.28(3)°,Z= 4.1236 diffractometer data (I> 3σ) were refined by least‐squares methods with anisotropic temperature factors for the non‐H atoms toR= 0.070.The packing arrangement for both forms shows a layer‐like structure with very similar packing coefficients,k= 0.7085 for the pure enantiomer andk= 0.7014 for the racemic form.
Growth and characterization of mixed neodymium praseodymium oxalatze decahydrate crystals in silica gel
Authors: Joseph Cyriak , Varghese George , Ittyachen M. A. 
Published: January 2007

AbstractMixed single crystals of neodymium praseodymium oxalate decahydrate were grown from silica gel by controlled reaction of rare earth nitrates with oxalic acid. The crystals were characterized using X‐ray powder diffraction and optical absorption studies.
Influence of synthesis and postgrowth treatment conditions on the structural homogeneity of YBa2Cu3Ox single crystals
Authors: Ivanova T. I. , Yu. Vlasov M. , Moshkin S. V. , Frank‐kamenetskaya O. V. , Kuzmina M. A. 
Published: January 2007

AbstractThe effect of synthesis and postgrowth treatment (by annealing at various temperatures and partial oxygen pressures) conditions on structural homogeneity of YBa2Cu3Ox single crystals has been studied. The obtaining of single crystals with both high oxygen content and high critical temperatures Tc has been optimized. The wide range of postgrowth treatment conditions proposed allows to receive single crystals with given oxygen content from 6.2 to 7.0.
Dielectric characteristics of neodymium heptamolybdate crystals grown by gel encapsulation technique
Authors: Bhat Sushma , Khosa S. K. , Kotru Dr. P. N. , Tandon R. P. 
Published: January 2007

AbstractResults obtained from the dielectric studies of neodymium heptamolybdate crystals grown in the system Nd(NO3)3 –MoO3 –NH4OH– HNO3 —Na2SiO3 by gel encapsulation technique are presented. The variation of dielectric constant (ε′), dielectric loss (tanδ) and conductivity (σ) with frequency at different temperatures is studied. The dielectric constant of the material increases sharply, attains a peak value and then decreases rapidly, as material's temperature rises from room temperature to higher degrees. The temperature at which the peak value is attained is the transition temperature of the material. Dielectric loss (tan δ) follows almost a similar behaviour. The conductivity (σ) is also found to be temperature‐and frequency‐dependent. This sharp rise in ε′ is attributed to the contribution from space charge polarization. Theoretically obtained data using the expression ε′ = a0 + a1 T2 and —In σ = a + b(T — T0)2 for T < T0) fits very well with the experimentally obtained data indicating that space charge polarization increases as some power of temperature larger than one.
Growth and Characterisation of Gel‐grown Lead(II)Chloride and Lead(II)Bromide Single Crystals
Authors: Sagayaraj P. , Sivanesan S. , Gobinathan R. 
Published: January 2007

AbstractSingle crystals of pure and doped lead(II)chloride and lead(II)bromide were grown by gel technique employing a modified two‐stage chemical reaction. Methods to minimise the predomination of needle morphology during the growth of these crystals have been investigated and the results are discussed. The grown crystals were characterised by optical transmission spectrum. Undoped and monovalent cation (K+, Na+, Cu+, Ag+ and Hg+) doped crystals of PbCl2 and PbBr2 were subjected to d.c. electrical conductivity studies. Using the log σT versus T−1 plot, the activation energies for the migration of anion vacancies in lead(II)halides are calculated. They are found to be less for the doped crystals than those of undoped ones.
Synthesis and Structure Study of the Complex [Cu2 (μ–C2O4) (C10H8N2)2(H2O)2] (C6H4COSO2N)2 Crystal Structure Containing Cu (II) Bipy Oxalato and Saccharin
Authors: Jianmin Li , Jingzhen Sun , Pengcheng Chen , Xintao Wu 
Published: January 2007

AbstractThe title compound has been synthesized and its crystal structure determined at room temperature. MW = 927.86, monoclinic, space group P21/c, Z = 2, a = 9.283(1) Å, b = 16.239(2) Å, c = 12.209(1) Å, β = 99.848(9)°. The crystal structure consists of repeated [Cu2(μ–C2O4)(C10H8N2)2 · (H2O)2]2 cations and non‐coordinated saccharin anions. Each copper ion is in a square pyrimidal environment with two oxalate oxygen and two bipyridine nitrogen atoms as a base and one water molecule at the apex. The two copper ions are bridged by oxalato and the distance is 5.138 Å.
Intergrowth Structures of YBA2Cu3Ox Single Crystals with Oxygen Inhomogeneity
Authors: Ivanova T. I. , Frank‐Kamenetskaya O. V. , Drits V. A. , Kastowsky M. , Bradaczek H. 
Published: January 2007

AbstractThe diffraction pattern simulation of four YBa2Cu3Ox single crystals with inhomogeneous distribution was successfully carried out on the base of the theory of X‐ray diffraction by disordered interstratified structures. The specific feature of their two‐component irregular mixed‐layered structures is the total segregation of layers with various oxygen content that led to the formation of so‐called intergrowth structures. The concentration of admixture layers varied from 10 to 40% while oxygen content difference within the crystal ranged from 0.5 to 0.3. In one of the crystals the fluctutations of layer heights corresponded to oxygen variation from 6.2 to 7.0.
Twins in GaAs Crystals Grown by the Vertical Gradient Freeze Technique
Authors: Koh H. J. , Fukuda T. , Choi M. H. , Park I. S. 
Published: January 2007

AbstractThe growth of facets and the generation of twins on <100> VGF (vertical gradient freeze technique) grown GaAs were investigated using DSL (diluted Sirtl‐like etchant with light) photoetching and transmission X‐ray topography. Due to the polarity of the (111) plane in GaAs, As facets are larger and more irregular than Ga facets and twins always occur on As facets. Twins are initiated at the change of boundary condition which is affected by temperature gradient and crucible shape. The mechanism of twin generation is explained by considering the edge concavity at the solid‐liquid interface and the supercooling required for initial nucleation of a facet. Twins are more often produced in Si‐doped crystals than undoped ones due to the constitutional supercooling.
Comparative Dielectric Investigations on Nematic Liquid Crystals with Aerosil
Authors: Tschierske S. , Yaroshchuk O. V. , Kresse H. 
Published: January 2007

AbstractDielectric measurements on a nematic room temperature mixture and the mixture with 20% aerosil were carried out. Addition of aerosil results in a small increase of the clearing temperature and in increasing relaxation frequency for the reorientation around the short molecular axis. The results are interpreted as orientation effect of the nematic sample at the fractal aerosil.
Modified Growth of Mercuric Iodide Crystals from the Vapour Phase
Authors: Li Associate Pro. Zheng‐Hui , Li Wei‐Tang , Liu Jun , Zhu Shi‐Fu , Zhao Bei‐Jun , Yuan Hong , Xu Hua‐Peng 
Published: January 2007

AbstractThe Hgl2 single crystal with shiny natural crystal planes, low density of dislocation, and 350 g in weight has been grown by a new technique of modified vapoir phase located point method. The perfection and nuclear spectroscopic performance of the grown crystals are also studied.
Growth and Character of the Transition Spectrum of Nd‐doped K2La(NO3)5 · 2 H2O Crystals
Authors: Fang C. S. , Zhuo H. S. , Yang Z. H. , Fang L. , Sherwood J. N. 
Published: January 2007

AbstractPotassium lanthanum nitrate dihydrate (KLN) is a new nonlinear optical crystal. An Nd‐doped potassium lanthanum nitrate (KLNN), was grown. As the first on this crystal and its characters of growth, thermal, spectral, and nonlinear optic properties is reported. KLNN crystal will be a useful material in frequency conversion of generating blue‐green laser.
Study of the Growth Morphology of Ammonium Oxalate Monohydrate Crystals Obtained from Aqueous Solutions
Authors: Mielniczek‐Brzóska E. , Sangwal K. 
Published: January 2007

AbstractThe experimental results of the growth morphology of ammonium oxalate monohydrate [(NH4)2C2O4 · H2O; AO] single crystals obtained from aqueous solutions at 30 and 40 °C and supersaturation up to 9% are presented. The observations are compared with the theoretical morphology predicted by PBC analysis and Braivais‐Donnay‐Harker law.
Classification of Mechanoluminescence
Authors: Chandra B. P. , Rathore A. S. 
Published: January 2007

AbstractOn the basis of the processes involved in inducing luminescence, mechanoluminescence (ML) may be classified into different types, such as: (i) piezo‐electrification‐induced fracto ML, (ii) defective‐phase piezo‐electrification‐induced fracto ML, (iii) charged dislocation electrification‐induced fracto ML, (iv) baro diffusion electrification‐induced fracto ML, (v) chemically‐induced fracto ML, (vi) thermally stimulated fracto ML, (vii) incandescent fracto ML, (viii) stress perturbation‐induced fracto ML, (ix) thermal excitation‐induced fracto ML, (x) mechanically excited ML, (xi) deep trap‐induced fracto ML, (xii) dislocation mechanical interaction‐induced plastico ML, (xiii) dislocation electrostatic interaction‐induced plastico ML, (xiv) charged dislocation electrification‐induced plastico ML, (xv) thermal excitation‐induced plastico ML, (xvi) dislocation mechanical interaction‐induced elastico ML, (xvii) dislocation electrostatic interaction‐induced elastico ML, (xviii) thermal excitation‐induced elastico ML, (xix) electrically induced tribo ML, (xx) chemically‐induced tribo ML, (xix) electrically induced tribo ML, (xx) chemically‐induced tribo ML, and (xxi) thermally‐induced tribo ML. It is expected that the processes involving dislocation electrostatic interaction‐induced elastico ML and thermal excitation‐induced elastico ML may provide suitable ML materials in future.
On the Crystal Structure of Rare Earth Complexes with 2‐Ethylhexyl Phosphoric Acids
Authors: Bozukov L. N. , Milanova M. M. , Todorovsky D. S. 
Published: January 2007

AbstractThe crystal structure of the complexes of some rare‐earths (RE = La, Nd, Pr and Er) with bis‐ and mono‐(2‐ethylhexyl)phosphoric acids were studied by using the X‐ray powder diffraction. The results show that for all RE investigated, the complexes of the diester crystrallize in orthorombic symmetry and cell parameters have been determined. The complexes of the monoester have been found to be nanocrystalline or amorphous.
Trap Level Characterization of Synthetic Quartz
Authors: Gandhi Y. H. , Vyas P. R. , Joshi T. R. 
Published: January 2007

AbstractThermoluminescene (TL) of synthetic quartz specimens under different physical conditions is investigated. An analysis for one of the prominent glow peaks has been done using the peak shape method. Further, on the basis of extracted trap level spectroscopic information, the results are explained. It is found that with different physical conditions characteristics of trapping level changes systematically.
Convective Temperature Fluctuations in Liquid Gallium in Dependence on Static and Rotating Magnetic Fields
Authors: Dold P. , Benz K. W. 
Published: January 2007

AbstractThe influence of static axial, static transversal, and rotating magnetic fields on convective temperature fluctuations in liquid gallium (temperature range around 800 °C, Prandtl number 2.5 · 10−3) has been investigated. For a Rayleigh number of 6.3 · 10−5 (ΔT = 10°C, h = 50 mm), convective temperature fluctuations with peak to peak values of 3 °C have been measured. Depending on the strength, the frequency, and the configuration of the field, they could be eliminated to ΔT < 0.01 °C (static axial field of 182 mT), damped to a nearly periodic state with 0.1 °C amplitudes (static transversal field of 45 mT), or reduced to 0.03 °C oscillations by applying a rotating field.
Thermal Hysteresis Accompanying Incommensurate‐Commensurate Phase Transition in Mixed Crystals (K1‐xCsx)2ZnCl4
Authors: Ahn H. Y. , Jeong S. Y. , Jang M. S. , Chung W. S. 
Published: January 2007

AbstractThe mixed crystal (K1‐xCsx)2ZnCl4 with x = 0, 0.001, 0.01, 0.1, and 0.2 with optical quality has been grown by the Czochralski method. Using the Atomic Absorption Spectroscopy (AAS) and Energy Dispersive Spectroscopy (EDS), we determined the amount of Cs ion included in the mixed crystal. By using of DTA and DSC, we observed the change of Tc and Ti. The thermal hysteresis in the dielectric constants show strong dependence on the thermal process and on the amount of impurity which are explained by the influence of the thermal process and impurity, respectively on the creation, annihilation, and growth of discommensuration (DC).
Interactions between YBa2Cu3O7‐x and K2Co3
Authors: Vassilev G. P. 
Published: January 2007

AbstractThe interactions between YBa2Cu3O7‐x and K2CO3 have been studied using thermochemical methods, isothermal annealing of diffusion pairs, optical microscopy, X‐ray diffraction, and microprobe analyses. The experiments have shown existence of solubility of YBa2Cu3O7‐x or its constituents in both solid and liquid K2CO3. The barium ions are preferably dissolved in K2CO3, whereas potassium cations do not enter massively into the bulk of the YBa2Cu3O7‐x‐phase. A eutectic‐type phase diagram is supposed for the system K2CO3–YBa2Cu3O7‐x.The so called “green phase” Y2BaCuO5 and a K–Cu–O compound have been found in the contact zone at 813 °C while a “black phase” layer with nominal composition Y1.6Cu2.8O5.4 has grown at 707 °C.
Optical Investigation of Defects in p‐type CuInSe2Single Crystals
Authors: Neumann H. , Jones P. A. , Sobotta H. , Hörig W. , Tomlinson R. D. , Yakushev M. V. 
Published: January 2007

AbstractOptical absorption spectra in the photon energy range from 0.03 to 1.1 eV and photoreflectance spectra in the range of the fundamental edge are measured on p‐type CuInSe2single crystals. Besides a dominant contribution to the absorption coefficient due to intervalence band transitions below about 0.75 eV the spectra revealed five additional structures that can be ascribed to defect induced optical transitions with characteristic energies between 0.48 and 0.72 eV. Based on a comparison of the near‐edge optical absorption and photoreflectance spectra a shallow defect (donor or acceptor) with an ionisation energy of about 46 meV was identified.
Magnetic Moment and Susceptibility Measurements of Mixed Rare Earth Oxalate Crystals
Authors: Joseph Cyriac , Varghese George , Ittyachen M. A. 
Published: January 2007

AbstractThe growth of double rare earth oxalate crystals with a general chemical formula AB(C2O4)3 · 10 H2O (where A and H are Nd, Pr and Sm) is reported. The variation of the magnetic moment of these crystals with an external field is studied and the magnetic susceptibility and the effective magnetic moment are calculated. The observed effective magnetic moment of the crystals are in good agreement with those calculated on theoretical grounds.
The Nature of One‐sided Intergrowths on (001) of Triclinic Centrosymmetric K2Cr2O7
Authors: Heide G. , Follner H. 
Published: January 2007

AbstractSystematic composite crystal growth can arise when larger crystals of the same type exhibit oriented intergrowth. One example of this is potassium dichromate (P1) which SHUBNIKOV first described in 1912. In highly supersaturated solutions, a one‐sided roughening of its crystals occurs on (001). Electron micrographs show that this is due to the growth of platelet‐shaped crystals. Optical and X‐ray methods as well as electron channeling and BACK‐KIKUCHI diffraction patterns have shown that the growths are predominantly parallel intergrowths, about 10% of which are twins according to [010].
Crystal Structure of Sarcosine Cadmium Chloride
Authors: Krishnakumar R. V. , Rameela M. P. , Natarajan S. 
Published: January 2007

AbstractSingle crystals of sarcosine cadmium chloride were crystallised from a saturated aqueous solution containing stoichiomeric amounts of sarcosine and cadmium chloride, in 1:1 proportion. The intensity data were collected using a CAD‐4 diffractometer with graphite monochromated MoKα, radiation. The crystal data are as follows: a = 6.916(1) Å, b = 13.855(3) Å, c = 7.981(1) Å, V = 764.1 Å · F.W. = 272.4, dexpt = 2.39 g · cm−3, dcalc = 2.368 g · cm−3, Z = 4 and the space group is P21/n. The structure has been solved to an R value of 0.023 for all the 1323 reflections with I > 2σ(I). The sarcosine molecule exists as zwitterion in the structure. The conformation of the sarcosine molecule is significantly changed due to the complexation of the molecule with cadmium chloride. The cadmium ion is found to have an octahedral coordination with both the oxygens of the carboxyl group of the amino acid and chlorines taking part in it. Since the complex has no water of hydration, only two hydrogen bonds of the types NH ‥ O and NH ‥ Cl are found.
Thermodiffusion and Morphological Stability in Convectionless Crystal Growth Systems from Melts and Melt‐Solutions
Authors: Rudolph P. , Boeck T. , Schmidt P. 
Published: January 2007

AbstractCrystal growth experiments of multicomponent systems under microgravity require an exact analysis of the diffusion phenomena in the nutrient fluid phase. The contribution of the Soret effect to the transport and distribution of matter in a convectionless casting arrangement for shaped crystal growth and in THM melt‐solution zones have been investigated. Some semiconductor systems were analysed from experimental (Bi1‐xSbx mixed crystals) and theoretical (PbTe, InP, GaAs, CdTe compounds) point of view. The criterion for constitutional supercooling was correspondingly modified. It has been distinguished between associated (AIVBVI, AIIBVI) and dissociated (AIII–BV) melt‐solutions, containing different species of diffusion (molecules or atoms, respectively).
The Crystal Structure of Hydrated Barium Copper Oxalate
Authors: Kasthuri V. Bangera , Rao P. Mohan , Nethaji M. 
Published: January 2007

AbstractBaCu(C2O42.6 H2O is triclinic, P1, with a = 6.5405(9), b = 9.202(3), c = 10.939(1) Å, α = 85.46(2), β = 79.22(1), γ = 80.45(2), V = 636.99(1) Å3, Z = 2, D0 = 2.14, Dc = 2.465 g. cm−3, R = 0.074, wR = 0.0746 for 2219 significant reflections |F0|≧ 6.0σF0. The barium has eleven coordinations and the coordination polyhedra is a capped antiprism. Six water oxygen atoms are coordinated whereas the other five are coming from the oxalate group. In the unit cell the molecules form a polymeric network. One lattice water molecule belongs to the coordinating water. The barium oxygen distances vary from 2.75 Å to 3.15 Å.