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A new approach to β-Ga 2 O 3 single crystal growth was studied, using the vertical Bridgman (VB) method in ambient air, while measuring the β-Ga 2 O 3 melting temperature and investigating the effects of crucible composition and shape. β-Ga 2 O 3 single crystals 25 mm in diameter were grown in platinum–rhodium alloy crucibles in ambient air, with no adhesion of the crystals to the crucible wall. Single crystal growth without a crystal seed was realized by (100) faceted growth with a growth direction perpendicular to the (100) faceted plane. [ABSTRACT FROM AUTHOR]

Bulk single crystals of the perovskite Li x La (1− x )/3 NbO 3 , which is one of the materials used as the solid electrolyte in all-solid lithium-ion batteries, have been grown for the first time by the directional solidification method. The ionic conductivity measured in the growth direction of a single crystal wafer of Li x La (1− x )/3 NbO 3 with x =0.08 showed a maximum value of 1.9×10 −4 Scm −1 . [ABSTRACT FROM AUTHOR]

A new technique is proposed in the traditional vertical Bridgman growth of sapphire crystals, in which thin-neck formation follows the initial seeding. Low-angle grain boundaries generated at the periphery of the seeding interface were eliminated at the thin neck, and the c-axis sapphire crystals with main bodies free from low-angle grain boundaries were grown. [ABSTRACT FROM AUTHOR]

Abstract: The growth of sapphire by the traditional vertical Bridgman (VB) method was studied by using various shapes of seed crystals and tungsten (W) crucibles shaped to match the seeds. Approximately 2-in. diameter, c-axis sapphire single crystals were reproducibly grown from three kinds of seed: thin, tapered and full diameter. Factors relating seed type to single-crystal growth are discussed, including the reproducibility of seeding processes, and the generation and elimination of low-angle grain boundaries (LAGBs). What was learned facilitated the subsequent growth of large-diameter, 3-, 4- and 6-in., c-axis single-crystal sapphires from full-diameter seeds. [Copyright &y& Elsevier]

Abstract: Few investigations of glass transition in the glass-forming materials [KNO3] x [Ca(NO3)2](1−x) (KCN:x), except at x =0.6 have been performed. The glass-forming range in KCN:x were obtained to be 0.58< x <0.64 from in situ observation using a stereoscope. For x <0.58 and x >0.64, crystal growth was observed. Brillouin scattering measurements in these mixture solutions, mainly for x values of the glass-forming region, have been performed as a function of temperature. From the thermal compressibilities β estimated by fitting analysis, their gradients from the glass transition temperature to about 170°C (=T cr) depend on x. This means that the ways of approaching the glass state from T cr are slightly different in KCN:x. This T cr is suggested to be a special temperature in the middle of the supercooling region during cooling and to specify the boundary from a liquid-like state to a solid-like state. [Copyright &y& Elsevier]

Morphologies of metallic inclusions observed in sapphire crystals grown by the vertical Bridgman (VB) technique using a tungsten (W) crucible were investigated. Square- or hexagonal-shaped inclusions 2-5 µm in size were observed in sapphire crystals around the interface between the seed and the grown crystal. It was found that such inclusions consisted of W metal used for the crucible. The morphology of some of the inclusions reflects a rhombic dodecahedron which is based on the cubic structure of W and is surrounded by {110} faces. It is probable that inclusions form in the sapphire melt during the crystal growth process, and then sink in the melt to the growth interface due to the high density of W. [ABSTRACT FROM AUTHOR]

Abstract: Defects related to oxygen and other impurities in piezoelectric langasite (La3Ga5SiO14; LGS) single crystals grown by the vertical Bridgman (VB) method was investigated. The resistivity of an LGS crystal grown in an Ar atmosphere was about one-order higher than that grown in air. However, after annealing in air it decreased to the same level as that of LGS crystal grown in air. The results of optical transmission spectra showed a broad adsorption peak around 500nm, corresponding to 2.5eV of energy level, in LGS crystals grown in air and grown in an Ar atmosphere. Since VB-grown LGS crystal was p-type, excess interstitial oxygen atoms, not oxygen vacancies, operate as an acceptor in the VB-LGS crystal. [Copyright &y& Elsevier]

Abstract: Dynamic interaction between dislocations and impurities in Si is investigated by using X-ray topography and the etch-pit technique from the viewpoint of Czochralski growth of Si crystals. Dislocation generation is effectively suppressed by doping of B and co-doping of B and Ge, which is originating in the immobilization of dislocations by preferential segregation of impurities. Dislocation velocity in motion is enhanced by increasing the concentration in B impurities. Change of the lattice parameter due to the impurity doping leads to the generation of misfit dislocations at the seed/crystal interface. [Copyright &y& Elsevier]