Pressure-induced phase transitions, electronic and magnetic properties of GdN

The electronic, magnetic and elastic properties of GdN in its three possible crystal structures: rock salt (RS), cesium chloride (CsCl), and zinc blende (ZB) are calculated using the ab-initio local spin density (LSDA) and the generalized gradient (GGA) approximations within the frame work of the density functional theory (DFT). We have performed our calculation at ambient (P = 0 GPa) and higher hydrostatic pressures; in order to study the effect of pressure on the physical properties and to predict possible pressure-induced crystallographic phase transitions. Three such transitions are predicted at −9.4, 113, and 23 GPa in the GGA approximation. Both LSDA and GGA calculations predicted that the ZB structure is half-metal and that the CsCl structure is metallic at ambient pressure.