Critical analysis of the vacancy induced magnetism in Scandium Nitride (ScN): An ab-initio study

• Published in: Journal of magnetism and magnetic materials 2016-09, Vol.413, p.19-24
• Main Authors: Missaoui, Jamil, Hamdi, Ilyes, Meskini, Noureddine
• Format: Article
• Language: English
• Subjects: Defects; Ferromagnetism; Formation energy; Magnetic interactions; Magnetic moment; Magnetism; Mathematical analysis; Percolation; Percolation threshold; Scandium; Strain; Vacancies; Vacancy
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2016.04.026

We have studied the origin of the magnetism induced by a neutral cation vacancy in rocksalt ScN using ab-initio calculations based on spin density functional theory. Our results showed that Sc vacancy induces a total local magnetic moment of 0.50μB. The main contributors to this induced magnetism are the 2p orbitals of nearest nitrogen atoms surrounding the vacancy. The spin polarization energy (defined as the energy difference between the spin polarized and non-polarized states) is well above the room-temperature energy. Furthermore, we have investigated the effect of an external strain on the induced magnetism. Our calculations showed that applying an external strain leads to a decrease of the stability of the magnetic state. Moreover, calculations of the magnetic interactions showed that the most stable configuration corresponds to the fifth nearest neighbor distance with a ferromagnetic state. Finally, using thermodynamic considerations, we demonstrated that the minimum defect concentration to achieve magnetic percolation cannot be reached at equilibrium conditions. However, we found that by applying an external strain, we could reduce the formation energy of the defect, achieving therefore the magnetic percolation. •ScN with cation vacancy leads to a non-vanishing total magnetic moment.•The spin polarization energy is well above temperature energy.•The magnetic state cannot be enhanced by strain.•The magnetic percolation can be achieved by applying an external strain.