Magnetic monolayer Li2N: Density Functional Theory calculations. (14th November 2017)

• Record Type: Journal Article
• Authors: Rahman, Gul; Ur Rahman, Altaf; Kanwal, Saima; Kratzer, Peter
• Is Part Of: Europhysics letters. Volume 119:Number 5(2017:Sep.)
• Publication Date: 2017-11-14
• Subjects: 73.22.-f -- 61.48.Gh -- 71.15.Mb; Physics -- Periodicals; Electronic journals; 530.05
• DOI: 10.1209/0295-5075/119/57002
• Languages: English
• ISSNs: 0295-5075

Abstract

Abstract: Density functional theory (DFT) calculations are used to investigate the electronic and magnetic structures of a two-dimensional (2D) monolayer Li2 N. It is shown that bulk Li3 N is a non-magnetic semiconductor. The non–spin-polarized DFT calculations show that p electrons of N in 2D Li2 N form a narrow band at the Fermi energy due to a low coordination number, and the density of states at the Fermi energy ( ) is increased as compared with bulk Li3 N. The large shows instability towards magnetism in Stoner's mean-field model. The spin-polarized calculations reveal that 2D Li2 N is magnetic without intrinsic or impurity defects. The magnetic moment of in 2D Li2 N is mainly contributed by the p z electrons of N, and the band structure shows half-metallic behavior. Dynamic instability in planar Li2 N monolayer is observed, but a buckled Li2 N monolayer is found to be dynamically stable. The ferromagnetic (FM) and antiferromagnetic (AFM) coupling between the N atoms is also investigated to access the exchange field strength. We found that planar (buckled) 2D Li2 N is a ferromagnetic material with Curie temperature T c of 161 (572) K.