Thermal expansion and characteristic temperature of dense modifications of boron nitride

Abstract The temperature dependence of the lattice parameters, the coefficients of thermal expansion, the mean square dynamic displacements of atoms in sphalerite (BN s ) and wurtzite (BN w ) modifications of boron nitride were studied by X-ray diffractometry. It has been shown that no significant anisotropy is observed in the thermal expansion and the change in thermal displacements of atoms in BN w . The characteristic temperatures for BN s , equal to 1730 ± 70 K, and for BN w , equal to 1460 ± 70 K, were determined from a change in the intensity of the diffraction maxima.