Compressibility of cubic vanadium mononitride

The equation of state of vanadium mononitride with a cubic rock-salt structure, δ-VN, was measured on quasi-hydrostatic compression in a diamond anvil cell to 29 GPa. From these data the bulk modulus of δ-VN, B0=300(6) GPa, and its first pressure derivative, B0'=3.6(6), were obtained. A comparison of the available data on B0 for δ-TiN, δ-ZrN, δ-HfN and δ-VN, extended by the present result, indicates a systematic agreement between the experimental B0-values from compression measurements and theoretical predictions based on the generalized gradient approximation (GGA) method. An increase of B0 with decreasing zero-pressure specific volume, earlier suggested for the group-4 and -5 transition metal mononitrides, is not confirmed.