Density functional theory studies of the SrC and SrN compounds

Abstract

The structural, magnetic, elastic, dynamical and thermodynamic properties of the SrC and SrN compounds were studied using density functional theory. We found that the CsCl and NaCl phases have the lowest energy configurations as a function of volume for SrC and SrN compounds considered respectively. The preferred ground state configuration for the SrN and SrC compounds is the ferromagnetic configuration with the exception of the CsCl and tetragonal phases in the SrC compound. From the elastic properties calculation, we obtained that only the NaCl, ZB and WZ phases are elastically stable. The dynamical properties calculation of the elastically stable SrN and SrC compounds showed that the NaCl and ZB phases are thermodynamically stable. The stable phases were found to have half-metallic (HM) magnetic nature attributed to the spin-polarized 2p orbitals of the nitrogen and carbon atoms in the SrN and SrC compounds respectively. The calculated magnetic moments for the SrN and SrC compounds are 1 μB and 2 μB per formula unit, respectively. The calculated HM gaps for the SrN and SrC compounds using the GGA-PBEsol (mBJ-GGA-PBEsol) are 0.27 eV (1.54 eV) and 0.27 eV (1.44 eV) in the NaCl phase, and 0.57 eV (1.77eV) and 0.77eV (1.86 eV) in the ZB phase