Formation of Cubic Boron Nitride from Rhombohedral Boron Nitride by Explosive Shock Compression

Abstract

When rhombohedral BN, which has a layer structure with a three‐layered stacking sequence, was shock‐compressed at 40, 60, and 100 GPa, it was converted to cubic BN. Hexagonal BN was converted to wurtzite‐type BN under the same conditions. These results indicate that the transformation proceeds by a diffusionless mechanism in which the stacking sequence of the BN layers in the starting materials is retained during the process.