C-type cubic yttrium oxide single crystals were successfully grown electrochemically by applying the Y3+ ion conducting solid electrolyte of Y-2(MoO4)(3) at 900 degreesC. The growth of the single crystal is regulated by the electrolysis condition, and the average crystal size can be intentionally controlled from 0.39 to 0.94 mum by adjusting the electrolysis period. Although single crystal growth of such a refractory oxide as Y2O3 is considerably difficult by the conventional thermal heating-cooling procedures via melt because of high melting point of Y2O3 (ca. 2376 degreesC), the present electrochemical single crystal growth is simply applicable at moderate temperatures at around 900 degreesC. (C) 2004 Elsevier B.V. All rights reserved.