First-principles studies of the electronic structure and magnetism in fayalites:: M2SiO4 (M = Fe and Co)

[摘要] The electronic structure and magnetism in fayalites M2SiO4 (M = Fe and Co) have been studied by density functional theory within the generalized gradient approximation with the on-site Coulomb energy taken into account (GGA + U). Stable insulating antiferromagnetic solutions are obtained. It is found that the gap opening in these fayalites results mainly from strong on-site Coulomb interactions of the magnetic atoms. In the band structures, the conduction bands originate mainly from the M(3d) orbitals of M2SiO4. The top of valence bands consists of the Fe (3d) orbitals in Fe2SiO4, and of the Co(3d)-O(2p) hybridization in Co2SiO4. All calculated orbital magnetic moments are very small. (C) 2004 Elsevier B.V. All rights reserved.

[发布日期] 2004-11-01

[效力级别]  Proceedings Paper

[关键词] fayalite;electronic structure;magnetism;density functional theory