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Single Crystal Growth (single + crystal_growth)
Selected AbstractsChemInform Abstract: Stoichiometric Single Crystal Growth of AgGaS2 by Iodine Transport Method and Characterization.CHEMINFORM, Issue 7 2009P. Prabukanthan Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Single Crystal Growth of Manganese Gallium Nitride Using Mn,Ga,Na Melt.CHEMINFORM, Issue 13 2004Masato Aoki Abstract For Abstract see ChemInform Abstract in Full Text. [source] Single Crystal Growth, Bonding Analysis and Superconductivity of V2Ga5.CHEMINFORM, Issue 7 2003Kim C. Lobring Abstract For Abstract see ChemInform Abstract in Full Text. [source] Crystal growth and scintillating properties of (Pr,Si)-doped YAlO3CRYSTAL RESEARCH AND TECHNOLOGY, Issue 12 2007M. Zhuravleva Abstract This paper deals with Pr-doped and Pr, Si-codoped YAlO3 single crystal growth by the micro-pulling-down method and investigation of their spectroscopic and scintillating properties. The Pr3+ 5d -4f radioluminescence intensity is more than 10 times higher than that of Bi4Ge3O12 standard sample, but the Si-codoping decreases it. Absorption spectra of as-grown and air-annealed Si,Pr-codoped YAlO3 samples show along with an onset of 4f -5d transition round 230 nm the induced absorption band at 400 nm which possibly related to a hole center absorption (Pr4+ or O - ). Thermoluminescence measurements above the room temperature were performed in order to monitor deep electron traps. Strong concentration dependence of thermoluminescence was observed for Pr:YAlO3 glow curves. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Optimization of control parameters of cadmium zinc telluride Bridgman single crystal growthCRYSTAL RESEARCH AND TECHNOLOGY, Issue 8 2007Liu Juncheng Abstract The temperature gradient within a furnace chamber and the crucible pull rate are the key control parameters for cadmium zinc telluride Bridgman single crystal growth. Their effects on the heat and mass transfer in front of the solid-liquid interface and the solute segregation in the grown crystal were investigated with numerical modeling. With an increase of the temperature gradient, the convection intensity in the melt in front of the solid-liquid interface increases almost proportionally to the temperature gradient. The interface concavity decreases rapidly at faster crucible pull rates, while it increases at slow pull rates. Moreover, the solute concentration gradient in the melt in front of the solid-liquid interface decreases significantly, as does the radial solute segregation in the grown crystal. In general, a decrease of the pull rate leads to a strong decrease of the concavity of the solid-liquid interface and of the radial solute segregation in the grown crystal, while the axial solute segregation in the grown crystal increases slightly. A combination of a low crucible pull rate with a medium temperature gradient within the furnace chamber will make the radial solute segregation of the grown crystal vanish. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Global simulation of a Czochralski furnace for silicon crystal growth against the assumed thermophysical propertiesCRYSTAL RESEARCH AND TECHNOLOGY, Issue 7 2006Y. R. Li Abstract In order to understand the effects of the thermophysical properties of the melt on the transport phenomena in the Czochralski (Cz) furnace for the single crystal growth of silicon, a set of global analyses of momentum, heat and mass transfer in small Cz furnace (crucible diameter: 7.2 cm, crystal diameter: 3.5 cm, operated in a 10 Torr argon flow environment) was carried out using the finite-element method. The global analysis assumed a pseudosteady axisymmetric state with laminar flow. The results show that different thermophysical properties will bring different variations of the heater power, the deflection of the melt/crystal interface, the axial temperature gradient in the crystal on the center of the melt/crystal interface and the average oxygen concentration along the melt/crystal interface. The application of the axial magnetic field is insensitive to this effect. This analysis reveals the importance of the determination of the thermophysical property in numerical simulation. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Grain Growth Control and Solid-State Crystal Growth by Li2O/PbO Addition and Dislocation Introduction in the PMN,35PT SystemJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 4 2006Min-Soo Kim Grain growth behavior and solid-state single crystal growth (SSCG) in the Pb(Mg1/3Nb2/3)O3,35 mol% PbTiO3 (PMN,35PT) system have been investigated with varying Li2O/PbO ratios. The effect of dislocation density on crystal growth has also been studied. For SSCG, a BaTiO3 single-crystal seed was embedded in a polycrystalline PMN,PT matrix. During annealing, a PMN,PT single crystal grew from the seed at the cost of the small matrix grains. Addition of Li2O dopant first enhanced and then reduced abnormal grain growth in the matrix. In the 2 mol% Li2O and 6 mol% PbO excess PMN,PT samples annealed at 1200°C, considerable single-crystal growth occurred without formation of abnormally large grains in the matrix. Increasing the dislocation density in the BaTiO3 seed crystal resulted in enhanced growth of single crystals. These results were explained in terms of interface reaction-controlled nucleation and growth, based on crystal growth theories. [source] Cover Picture: Laser Phys.LASER PHYSICS LETTERS, Issue 7 2010Lett. It's known that single crystals of germanate melilites, such as Ba2ZnGe2O7 and Sr2MgGe2O7, show a congruent melting behavior at about 1450 °C. Crystals of Sr2MgGe2O7 were grown from melt of stoichiometric composition by the Czochralski technique using a seed crystal orientation (and pulling direction) along [001], a pulling velocity of 2,3 mm/h and crystal rotation of 40,60 rad/min. For single crystal growth of Ba2ZnGe2O7 a melt with a surplus of ,4 wt.% BaO and ,5 wt.% GeO2 proved to be useful. Grown crystals are of dimensions up to 25 mm in length and 18 mm in diameter for Sr2MgGe2O7 and of up to 15 mm in length and in diameter for Ba2ZnGe2O7. In Cover picture an example of a grown crystal of Sr2MgGe2O7 is presented. (Cover picture: A.A. Kaminskii, L. Bohatý, et al., pp. 528,543, in this issue) (© 2010 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source] UV emission on a Si substrate: Optical and structural properties of ,-CuCl on Si grown using liquid phase epitaxy techniquesPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 5 2009A. Cowley Abstract Considerable research is being carried out in the area of wide band gap semiconductor materials for light emission in the 300,400 nm spectral range. Current materials being used for such devices are typically based on II,VI and III-nitride compounds and variants thereof. However, one of the major obstacles to the successful fabrication of III-N devices is lattice mismatch-induced high dislocation densities for epitaxially grown layers on non-native substrates. ,-CuCl is a direct bandgap material and an ionic wide bandgap I,VII semiconductor with a room temperature free exciton binding energy of ,190 meV (compared to ,25 meV and ,60 meV for GaN and ZnO, respectively) and has a band gap of 3.4 eV (, , 366 nm). The lattice constant of ,-CuCl (0.541 nm) is closely matched to that of Si (0.543 nm). This could, in principle, lead to the development of optoelectronic systems based on CuCl grown on Si. Research towards this end has successfully yielded polycrystalline ,-CuCl on Si(100) and Si(111) using vacuum-based deposition techniques [1]. We report on developments towards achieving single crystal growth of CuCl from solution via Liquid Phase Epitaxy (LPE) based techniques. Work is being carried out using alkali halide flux compounds to depress the liquidus temperature of the CuCl below its solid phase wurtzite-zincblende transition temperature (407 °C [2]) for solution based epitaxy on Si substrates. Initial results show that the resulting KCl flux-driven deposition of CuCl onto the Si substrate has yielded superior photoluminescence (PL) and X-ray excited optical luminescence (XEOL) behavior relative to comparitively observed spectra for GaN or polycrystalline CuCl. This enhancement is believed to be caused by an interaction between the KCl and CuCl material subsequent to the deposition process, perhaps involving a reduction in Cl vacancy distributions in CuCl. This paper presents a detailed discussion of a CuCl LPE growth system as well as the characterization of deposited materials using X-ray diffraction (XRD), room temperature and low temperature PL, and XEOL. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] InxGa1,xAs single crystal growth by dispersing local misfit stressPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 11 2006Hiroaki Miyata Abstract We succeeded in growing a single crystal by dispersing the misfit stress around an initial solid-liquid interface in In0.3Ga0.7As ternary bulk crystal growth. We gradually increased concentration of indium arsenide so that the local misfit stress could be smaller than critical resolved shear stress. The traveling lqiuidus-zone (TLZ) method was applied for growing crystals. To grow a single In0.3Ga0.7As crystal, an In0.1Ga0.9As single crystal region was grown first on a GaAs seed. Then the concentration of indium arsenide was gradually increased up to In0.3Ga0.7As by lowering temperature at the interface. As a result, In0.3Ga0.7As single crystals of 2 mm in thickness, 10 mm in width and more than 25 mm in length were successfully obtained. Mean value of full width half maximum (FWHM) of X-ray rocking curves in the In0.3Ga0.7As grown crystal was 0.116°. It is not small enough but it will be improved by increasing compositional homogeneity. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Bulk GaN single crystal growth for substrate by solvent-thermal methodPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 10 2004T. I. Shin Abstract We grew bulk GaN single crystals by solvent-thermal method. GaN single crystals were synthesized at 600,800 °C and 6,8 MPa of N2 gas for 200 h. We used 99% pure Na as a flux. The mole fraction of Na / (Na+Ga) were 0.30,0.67. A pyramid GaN single crystal having a size of 1,3 mm grew on the bottom and wall of a sintered BN crucible. We confirmed wurtzite structure GaN which was grown single crystal through XRD pattern. The chemical composition was investigated by EPMA. Raman spectroscopy yielded narrow peaks representing only the modes allowed for the wurtzite structure. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | ||||||||||