Equation of state of hexagonal boron nitride

Fuchizaki, Kazuhiro*; Nakamichi, Takeshi*; Saito, Hiroyuki; Katayama, Yoshinori

Diffraction data from hexagonal boron nitride were measured through in situ synchrotron X-ray measurements under pressures and temperatures up to about 8GPa and 1000K, respectively. They were analyzed in the light of Birch Murnaghan's and Parsafar Mason's equations of state. The isothermal bulk moduli at ambient conditions obtained from these equations almost coincide. However, the value, about 20GPa, is appreciably smaller than the one reported previously. The X-ray diffraction patterns by which the current result is justified are presented. The possible origin of a large discrepancy in the values is discussed.