FLUX GROWTH OF PEROVSKITE-TYPE RALO(3) SINGLE-CRYSTALS

Single crystals of RAlO(3) (R = La-Lu) were successfully obtained at atmospheric pressure by a flux method using KF. According to the R element, solute was prepared by three different processes. Single crystals of RAlO(3) (R = Ce, Pr and Tb) were grown in He atmosphere to prevent oxidation, and others were grown in air. Single crystals are transparent cubes. In the case of the growth experiment of NdAlO3, the solute was prepared from alcoholates and it was very smoothly dissolved in the KF flux. As a result, crystals of NdAlO3 were grown up to 300-600 mu m in size compared with 30-60 mu m for other phases. Single crystals of LuAlO3 were successfully obtained for the first time by this flux method at ambient pressure in air. RAlO(3) for R = La, Pr and Nd shows trigonal symmetry with a rhombohedral lattice, and CeAlO3 crystallizes in tetragonal symmetry. Others show orthorhombic symmetry. The lattice distortion from an ideal cubic perovskite structure is smaller in the aluminates of rare earth elements with lower atomic numbers in each structure group.