Crystal growth of KTa_1-xNb_xO₃ (0<x≤0.04) solid solutions by a slow-cooling method

For ferroelectric quantum-limit investigations, KTa1-xNbxO3 solid solutions with low Nb concentrations are of current interest. Large crystals (25×25×12 mm3) have been grown by a slow-cooling method using the accelerated crucible rotation technique ACRT. The experiments are described in some detail, and the experimental parameters related to the various types of inhomogeneity observed in such solid solutions. Moreover, the concentration gradient and the striations have been investigated by acoustic resonance and electron-microprobe measurements. Very faint striations may still exist in the crystals obtained as indicated by weak strain patterns in polarized light. These striations have been minimized in the ACRT experiments. © 1982.