Growth of Ca4YO(BO3)(3) crystals by vertical Bridgman method

Growth of single crystals of Ca4YO(BO3)(3) (YCOB) by the vertical Bridgman method is reported in this paper. By using near-sealed Pt crucibles to prev ent volatilization of B2O3, the high-optical-quality YCOB crystals of 25mm diameter and more than 40 mm in length have been grown at the furnace tempe rature of 50-80 degreesC above the melting point of YCOB and the crucible l owering rates of 0.2-0.6 mm/h. Owing to the low vertical and radial tempera ture gradient, crack-free YCOB crystals have been obtained in the (0 10) an d (001) directions. At the top of a YCOB boule, the dislocation density was found to decrease from the center to the outer area, and the average dislo cation density is about 600/cm(2). (C) 2001 Elsevier Science B.V. All right s reserved.