Band structure calculation and structural stability of high pressure phases of EuSe

Abstract

Ab-initio band structure calculations have been carried out to find the pressure-induced structural transitions and structural stability of the magnetic semiconductor EuSe. The first principal tight-binding linear muffin-tin orbital method (TB-LMTO) within local density approximation (LDA) has been used to study this band structure. While the magnetic phase stability is determined from the total energy calculations within the atomic-sphere approximation (ASA) for both the non-magnetic (NM) and magnetic (M) phases. Our pure theoretical calculations show that: (1) at ambient pressure, the M phase is more stable than the NM phase; and (2) it exhibits a phase transition from NaCl (B1) type to CsCl (B2) type structure at around 9.48 GPa. Although the calculated lattice parameter, transition pressure, volume of collapse is found to be less than the experimentally observed value, but this has been explained from the fact that the calculation has been carried out at 0 K while the experiments have been performed at room temperature. The bulk modulus and magnetic moments are found to be in agreement with earlier experimental result.