High pressure band structures and structural stability of EuS

Band structure calculations were carried out to study the pressure-induced structural transitions and structural stability of the magnetic compound EuS. The compressibility behavior of this compound was discussed in the light of the changes occurring in the electronic structure. The density of states (DOS), Fermi energy (Ef), lattice parameters at different pressures for both phases were also discussed. The first principal tight-binding linear muffin-tin orbital method (TB-LMTO) within local density approximation (LDA) was used to study the band structure. The magnetic phase stability was determined from the total energy calculations within the atomic-sphere approximation (ASA) for both the non-magnetic (NM) and magnetic (M) phases. These theoretical calculations clearly indicate that both at ambient as well as at high pressures, the M phase is more stable than the NM phase. The phase transition from NaCl (B1) type to CsCl (B2) type structure was found to occur at around 21.1 GPa, which is slightly less than the experimentally observed value (21.5 GPa). The bulk modulus and magnetic moments are found to be in agreement with earlier experimental results.