Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8152578 | Journal of Magnetism and Magnetic Materials | 2018 | 8 Pages |
Abstract
Ab initio calculations based on density functional theory with local spin density approximation are used to study defects-driven magnetism in bulk α-Li3N. Our calculations show that bulk Li3N is a non-magnetic semiconductor. Two types of Li vacancies (Li-I and Li-II) are considered, and Li-vacancies (either Li-I or Li-II type) can induce magnetism in Li3N with a total magnetic moment of 1.0 μB which arises mainly due to partially occupied N-p-orbitals around the Li vacancies. The defect formation energies dictate that Li-II vacancy, which is in the Li2N plane, is thermodynamically more stable as compared with Li-I vacancy. The electronic structures of Li-vacancies show half-metallic behavior. On the other hand N-vacancy does not induce magnetism and has a larger formation energy than Li-vacancies. N vacancy derived bands at the Fermi energy are mainly contributed by the Li atoms. Carbon is also doped at Li-I and Li-II sites, and it is expected that doping C at Li-I site is thermodynamically more stable as compared with Li-II site. Carbon can induce metallicity with zero magnetic moment when doped at Li-I site, whereas magnetism is observed when Li-II site is occupied by the C impurity atom and C-driven magnetism is spread over the N atoms as well. Carbon can also induce half-metallic magnetism when doped at N site in Li3N, and has a smaller defect formation energy as compared with Li-II site doping. The ferromagnetic (FM) and antiferromagnetic (AFM) coupling between the C atoms is also investigated, and we conclude that FM state is more stable than the AFM state.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Saima Kanwal, Gul Rahman,