The growth of YCa4O(BO3)(3) (YCOB), one of the rare-earth calcium oxyborate
family of crystals that melts nearly congruently is reported. Typical crys
tals produced in our laboratory are about 40 mm in diameter and 150 mm long
with good optical quality. The crystal has good potential to be used for s
elf-frequency doubling due to its excellent combination of nonlinear and la
ser properties. The single crystal growth of YCOB with different rare-earth
substitutions is presented. We find that the substitution limit is reduced
with either an increase or decrease in the ionic size of the substituted r
are-earth element. The melt also moves further away from congruently meltin
g with these substitutions. YCOB belongs to monoclinic crystal system. The
orientation relationship between the crystallographic axes (a, b, c) and op
tical indicatrix axes (X, Y, Z) is discussed. (C) 1999 Elsevier Science B.V
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