RELATIONSHIP BETWEEN STOICHIOMETRY AND PHYSICAL-PROPERTIES OF R(123)-TYPE (R=Y, RE) SINGLE-CRYSTALS

A relationship between the deviation of the cation sublattice from sto ichiometry, on the one hand, and the crystal symmetry, superconducting properties and optical spectra, on the other hand, has been analysed in R(123)-type single crystals, where R denotes Y or rare earth (RE) e lements. It has been shown that this relationship can be quantitativel y characterized by the deficiency of Cu sites d(Cu). Two regions of d( Cu) values have been distinguished, in which superconducting single cr ystals have been synthesized. The regularities of the redistribution o f the elements in the cation sublattice Of RE-doped single crystals of the (123)-type structure have been revealed.