Structural and electronic properties of Er-monopnictides under high pressure

摘要

We present the results of theoretical calculations on the structural, magnetic and electronic properties of Er-monopnictides using self-consistent first principles tight-binding linear-muffin-tin-orbital (TB-LMTO) method within the atomic-sphere approximation (ASA). Both spin-polarized and non-spin-polarized calculations are performed to check the magnetic stability of these compounds. We find that ErN, ErP and ErAs are metallic in ferromagnetic (FM) phase in both the spin channels and stable in NaCl-type (B_1) structure at ambient pressure. We predict NaCl-type (B_1) to CsCl-type (B_2) structural phase transition in ErN, ErP and ErAs at pressures of 146.1, 60.2 and 53.2 GPa, respectively and remain metallic ferromagnetic at high pressure. We calculate equilibrium lattice constants (a), bulkmodulus (B), magnetic moments (u_B) and electronic properties of these compounds in B_1 and B_2 phases and compare with available experimental and theoretical results.