P-V-T equation of state of boron carbide

We report the P-V-T equation of state measurements of B(4)C to 50 GPa and approximately 2500 K in laser-heated diamond anvil cells. We obtain an ambient temperature, third-order Birch–Murnaghan fit to the P-V data that yields a bulk modulus K(0) of 221(2) GPa and derivative, (dK/dP)(0) of 3.3(1). These were used in fits with both a Mie–Grüneisen–Debye model and a temperature-dependent, Birch–Murnaghan equation of state that includes thermal pressure estimated by thermal expansion (α) and a temperature-dependent bulk modulus (dK(0)/dT). The ambient pressure thermal expansion coefficient (α(0 )+ α(1)T), Grüneisen γ(V) = γ(0)(V/V(0))(q) and volume-dependent Debye temperature, were used as input parameters for these fits and found to be sufficient to describe the data in the whole P-T range of this study. This article is part of the theme issue ‘Exploring the length scales, timescales and chemistry of challenging materials (Part 1)’.