METHOD FOR GROWING HEXABORIDE RARE EARTH SINGLE CRYSTAL

摘要

PROBLEM TO BE SOLVED: To obtain the above single crystal which does not include crystal defects, is useful as a high-luminance thermion radiative material and has a long life by growing the single crystal under specific conditions in a method for growing the specified hexaboride rare earth single crystal by a floating zone method. ;SOLUTION: This method is for growing the hexaboride rare earth single crystal expressed by formula ReB_6+x [Re is La, Ce or (La, Ce); 0.05≤x≤0.2]. The single crystal is grown by using a raw material rod contg. a boron component at a ratio higher than in the stoichiometric compsn. in the method. More preferably, the B content in the raw material rod is specified to B/Re20 by atomic ratio with respect to the stoichiometric compsn. of ReB₆. The speed of growing the crystal is preferably set at 0.2 to 3.0cm/hr. The rate of supplying the raw material rod to the melting zone is preferably set higher by 10 to 30% than the rate of growing the crystal.;COPYRIGHT: (C)1997,JPO