Growth of Bi4Ge3O12 single crystal by the micro-pulling-down method from bismuth rich composition

Bi4Ge3O12 (BGO) crystals are well-known scintillator material. In this study, BGO single crystal fibers were successfully grown by the micro-pulling-down method with resistance heating system. Considering the volatilization of bismuth, we grew fibers from two different Bi2O3 enriched composition (2.05 mol% Bi2O3-3 mol% GeO2 and 2.1 mol% Bi2O3-3 mol% GeO2). For the composition of Bi2O3 2.1 molar ratio, the best single crystal fibers were obtained for pulling-down rate equal to 0.08 mm/min. The grown fiber crystals from that composition were transparent and nearly colorless except for a slight yellowish tint at the end of the fibers. The distribution coefficient of the Bi and Ge ions in the grown fibers was measured. (C) 2002 Elsevier Science B.V. All rights reserved.