Thermoelastic equation of state of boron subphosphide B12P2

Compressibility of boron subphosphide B 12 P 2 has been studied under quasi-hydrostatic conditions up to 26 GPa and 2600 K using laser-heated diamond anvil cell and angle-dispersive synchrotron X-ray diffraction. 300-K data fit yields the values of bulk modulus B 0 = 192(11) GPa and its first pressure derivative B 0 ′ = 5.5(12). It has been found that at ambient pressure the thermal expansion is quasi-linear up to 1300 K with average volume expansion coefficient α = 17.4(1) × 10 −6 K −1 . The whole set of experimental p–V–T data is well described by the Anderson-Grüneisen model with δ T = 6.