제일원리계산방법에 의한 결정 구조에 따른 덩치 망간의 전자 구조와 자성 변화 연구

Abstract

덩치 망간의 평형상태에서의 결정구조와 자성 구조는 아주 복잡한 것으로 알려져 있다. 본 연구에서는 자성 연구에서 가장 적합한 방법으로 알려져 있는 Full-potential Linearized Augmented Plane Wave(FLAPW) 방법을 사용하여 격자상수의 함수로 면심입방 Mn과 체심입방 Mn의 계산 가능한 자성 상태(상자성, 강자성, 반강자성 상태)의 총에너지를 계산하여 결정구조에 따른 Mn의 자성 변화를 연구하였다. 계산 결과, 면심입방 Mn은 반강자성 상태가 안정하고 체심입방 Mn은 강자성상태가 안정한 것으로 밝혀졌다. 면심입방 Mn과 체심입방 Mn의 평형상태의 격자상수는 각각 6.750, 5.314 a.u. 이었고 자기모멘트는 1.15 μ_B과 0.85 μ_B인 것으로 계산되었다. 면심입방의 경우는 강자성 상태가, 체심입방의 경우는 반강자성 상태가 전혀 안정되지 못하는 것으로 나타났다.

Manganese is known to have a very complicated crystal structure due to its complex magnetism. In this study we investigated the magnetism of fee and bcc Mn as functions of lattice constants, using Full-potential Linearized Augmented Plane Wave(FLAPW) method and assuming para-, ferro-, and antifcrro-magnetic states. The anti ferromagnetic and ferromagnetic states were calculated to be energetically stable for fee Mn and bcc Mn, respectively. The lattice constants of fee and bcc Mn at equilibrium are 6.750 and 5.314 a.u. and the magnetic moments are 1.15 and 0.85 μ_B, respectively. The ferro- and antiferro-magnetic states are so unstable (not even metastable) that the states were converged to the other magnetic states in self-consistent calculations.

Manganese is known to have a very complicated crystal structure due to its complex magnetism. In this study we investigated the magnetism of fee and bcc Mn as functions of lattice constants, using Full-potential Linearized Augmented Plane Wave(FLAPW) method and assuming para-, ferro-, and antifcrro-magnetic states. The anti ferromagnetic and ferromagnetic states were calculated to be energetically stable for fee Mn and bcc Mn, respectively. The lattice constants of fee and bcc Mn at equilibrium are 6.750 and 5.314 a.u. and the magnetic moments are 1.15 and 0.85 μ_B, respectively. The ferro- and antiferro-magnetic states are so unstable (not even metastable) that the states were converged to the other magnetic states in self-consistent calculations.