Morphological changes of calcium hexaboride powder synthesized from condensed boric acid-polyol product

Abstract We previously reported a novel low-temperature synthesis method for calcium hexaboride (CaB 6 ) powder via the transient formation of boron carbide (B 4 C) using a condensed boric acid (H 3 BO 3 )-polyol product. In this study, the effect of the type of polyol on the morphology of the CaB 6 powder was investigated. Three types of polyol, glycerin, mannitol, and poly(vinyl alcohol) (PVA), were used for the preparation of condensed H 3 BO 3 -polyol products since the B 4 C particles prepared from these polyols exhibit different morphologies. CaB 6 powder was successfully synthesized at a low temperature of 1400 °C regardless of the polyol used. The size of the obtained CaB 6 particles varied with the polyol used, which reflected the size of the B 4 C particles prepared using the corresponding polyol. These results indicate that the morphology of the obtained CaB 6 powder is derived from that of the transiently formed B 4 C particles.