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

Ab-initio band structure calculations have been carried out to find the pre ssure-induced structural transitions and structural stability of the magnet ic 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 de termined from the total energy calculations within the atomic-sphere approx imation (ASA) for both the non-magnetic (NM) and magnetic (M) phases. Our p ure theoretical calculations show that: (1) at ambient pressure, the M phas e 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. Althoug h the calculated lattice parameter, transition pressure, volume of collapse is found to be less than the experimentally observed value, but this has b een 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 m odulus and magnetic moments are found to be in agreement with earlier exper imental result. (C) 1999 Elsevier Science Ltd. All rights reserved.