The growth of multicomponent oxide single crystals by stepanov's technique

This paper is concerned with the problems of growing multicomponent oxide compounds with the structures of pseudoilmenite, tetragonal potassium-tungsten bronze, garnet, silenite, and evlitine from the melt by Stepanov's technique. Single crystals of LiNbO 3, Sr x Ba 1− x Nb 2 O 6, Ca 3(VO 4) 2, Bi 12SiO 20, Bi 12GeO 20, Bi 4Ge 3O 12 and and Nd 3Ga 5O 12 were grown in an apparatus using RF heating of platinum crucibles in air. Platinum dies with plane and rectangular shapes were used. Stepanov's technique made it possible to increase several times the rates of solidification needed to obtain optically homogeneous single crystals. Optimum crystallographic directions of pulling of a crystallizing substance from various-profile dies were experimentally determined for crystals from various symmetry groups. An association of the shape of a growing crystal with the structural defects was established according to the Curie principle. The experimental data provided support for the growth of profiled multicomponent single crystals.