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The effect of B2O3 addition on La2−xSrxCuO4 (LSCO) single-crystal growth by traveling solvent floating zone technique was examined. Experimentally, it was found that addition of boron oxide to the solvent provides a reduction of the solvent penetration into the feed rod and better seeding. No influence of boron on the superconductivity characteristics of grown LSCO single crystals was found. As a result high-quality, subgrain and inclusion-free La2−xSrxCuO4 single crystals with x=0.0, 0.09 and 0.13 were prepared.

Single crystals of pure and Zn-doped CuGeO3 were successfully grown by the FZ and TSFZ methods using an infrared heating furnace. The grown crystals, typically about 5 mm in diameter and 30 mm in length, were crack-free, bright blue and transparent. The effective distribution coefficient of Zn into CuGeO3 was determined to be 0.26 for a Zn concentration of 0.03. Single crystals of Cu1 − xZnxGeO3 with homogeneous composition were grown by the TSFZ method using Zn-rich melts. The as-grown crystals were characterized by magnetization measurements, and the magnetic transitions are discussed.

In order to study these inhomogeneities, Ce-doped and undoped strontium-barium niobate (SBN) fibers were grown by a laser-heated pedestal growth (LHPG) technique in various Ce:Sr x Ba 1− x Nb 2 O 6 compositions along both c [001] and a [100] crystallographic axes. Specific optical inhomogeneities distributed in a radial manner (core effects) are observed in such crystals. Two-dimensional scanning electron microprobe analysis (SEPMA) indicated Ba enrichment and Sr decrease in the cores. An approximate control segregation coefficient (' k oA ) was introduced to characterize the segregation in the fibers. For different cations ' k oSr = 0.98, ' k oBa = 1.04 and ' k oNb = 0.99 were obtained which both determine and demonstrate the complexity of the inhomogeneities in the core in the radial direction.

Single crystals of Ba 1− x Sr x TiO 3 were grown by the floating zone (FZ) method using an infrared heating furnace. The grown crystals of Ba 1− x Sr x TiO 3 , typically 8 mm in diameter and 4 mm in length, were crack-free and yellowish transparent. Substitution of more than 1.2 at% Sr for Ba in BaTiO 3 was effective in preventing the formation of the hexagonal phase. It was found that Ba 1− x Sr x TiO 3 melts congruently at 1.5 at% Sr.

It was found that NdAlO 3 has a reversible phase transition at a temperature close to its melting point. Substitution of Y for Nd in NdAlO 3 was effective in stabilizing the high temperature phase. Crystals of Nd 1-x Y x AlO 3 (0≤x≤0.25) were grown by the floating zone (FZ) method using an infrared furnace. The crystals had some cracks, subgrain boundaries and domain structure, and 'also were not uniform in Y concentration due to supercooling

Single crystals of beryl grown by slow cooling from an impurity doped flux without a seed crystal have been grown and their habit modifications studied by SEM and optical microscopic observation. Transition metal doping using Fe 2 O 3 , Cr 2 O 3 , Mn 2 O 3 and alkali metal doping experiments were also carried out. Two characteristics, (1) the ratio (H/W), height to width of the crystals and (2) combination and relative development of crystal faces, were used as a measure of habit modifications. In general, as impurity doping increased, the crystals became slender and the second order prism disappeared. The ratio H/W was less in the larger crystals. This tendency can be attributed to the selective incorporation of impurity atoms on certain faces.

Single crystals of SrTa 2 0 6 and Ba 0.1 Sr 0.9 Ta 2 O 6 were grown by the floating zone method using an infrared heated furnace. The grown crystals of SrTa 2 0 6 and Ba 0.1 Sr 0.9 Ta 2 O 6 were about 5 mm in diameter and up to 35 mm long. The crystals of SrTa 2 O 6 showed a transition from the tetragonal structure to the orthorhombic structure at about 600 °C, whereas the crystals of Ba 0.1 Sr 0.9 Ta 2 O 6 exhibited the tetragonal structure without a phase transition. The dielectric constants ∈ of the SrTa 2 O 6 single crystals were independent of frequency and anisotropic with ∈ α =108 and ∈ c =128. However, ∈ c decreased as frequency increased for the Ba substituted crystals.

Single crystals of barium tetratitanate (BaTi 4 O 9 ) were grown by the floating zone method using an infrared heating furnace. The grown crystals were about 5 mm in diameter by 50 mm in length, colorless and transparent. BaTi 4 O 9 melts incongruently, so that in addition to BaTi 4 O 9 , also TiO 2 and BaTi 2 O 5 precipitated at the intial and final stages of growth. However, the middle section from which both ends of the grown crystals were eliminated was a single crystal, had a stoichiometric composition of BaTi 4 O 9 and was homogenous in composition.

In the system of MnTa2O6-FeTa2O6, Mn2+ was substituted up to about 80 at% for Fe2+ in trirutile-type FeTa2O6, and Fe2+ was substituted up to 13 at% for Mn2+ in MnTa2O6. In the MnNb2O6-MnTa2O6 system, all solid solutions had the columbite-typ structure. Single crystals of tantalite solid solutions having the composition of FexMn1−xTa2O6 (0.00 ≦ x ≦1.00) and Mn(TayNb1-y)2O6 (0.00 ≦ y ≦ 1.00) were grown by the floating zone method using an infrared heating furnace unde controlled atmosphere of oxygen pressure. Trirutile-type single crystals of FexMn1-xTa2O6 with 0.40 ≦ x ≦ 1.00 and col type single crystals of Mn(TayNb1-y)2O6 with 0.00 ≦ y ≦ 0.50 were obtained. The crystals were 5 mm in diameter by about length, and were crack-free, metallic lustrous and black.

Single crystals of titanite (CaTiSiO 5 ) were grown by the floating zone method using an infrared heating furnace. The single crystals, which were crack-free, dark blue and about 5 mm in diameter and 10 mm in length, were obtained in a nitrogen atmosphere. The grown crystals had a stoichiometric composition of CaTiSiO 5 . The titanite crystals underwent a reversible phase transition at 235 ±5°C; they were monoclinic with a space group of P2 1 /a at 20°C and became A2/a above 235°C. The dielectric constant ∈ was measured between 25 and 300°C; ∈ is 41.7 at 25°C and increased toits maximum value of 446 at 235°C.

High quality large single crystals of La2-xSrxCuO4 were grown by the travelling solvent floating zone method (TSFZ method). Crystals of up to about 6 mm diameter and 40 mm length were obtained. The composition of the grown crystals was uniform and was determined to be La1.86Sr0.14Cu0.97O3.89. The single crystals were superconductors with Tc = 37.5 K and ΔTc = 1.1 K, and had a significant anisotropy of the electrical resistivities at the non-superconducting state.

Single crystals of tapiolite (FeTa2O6) were grown by the floating zone method using an infrared heating furnace under a controlled atmosphere of oxygen partial pressure obtained with a CO2-CO gas mixture. The grown crystals were 5 mm in diameter by 50 mm in length, had a metallic luster and were homogeneous in composition. When the FeTa2O6 grown crystals were heated in air at 1000°C, FeTa2O6 was decomposed into disordered tapiolite (FeTaO4) and β-Ta2O5.