Nanoindentation measurements of a highly oriented wurtzite-Type boron nitride bulk crystal

Abstract

We succeeded in synthesizing a bulk crystal of wurtzite-Type boron nitride (w-BN) by the direct conversion method. The synthesized crystal was approximately 2mm wide and 350μm thick, and highly oriented to the c-Axis. We performed nanoindentation measurements on the c-plane of the w-BN crystal at room temperature to evaluate the mechanical properties of w-BN. The hardness and Young's modulus of w-BN from the obtained curves were simultaneously determined to be 54 + 2 and 860 + 40GPa, respectively. The underlying physical mechanism that dominates the mechanical properties of group-III nitride semiconductors is also examined.