Floating Zone Growth and High Temperature Hardness of Rare-Earth Hexaboride Crystals: LaB6, CeB6, PrB6, NdB6, and SmB6

Single crystals of rare-earth hexaborides, LaB6, CeB6, PrB6, NdB6, and SmB6, were prepared by the floating zone method. Their crystal quality increased as the atomic number of the rare-earth metals increased. The difference in the quality was explained from the hightemperature hardness and the growth temperature.