A Density Functional Theory Study on Al2CO-Based Diluted Magnetic Semiconductor

Abstract

To overcome the challenges related to diluted magnetic semiconductors (DMS), significant research efforts are currently underway to develop functional materials to fulfil the requirements of next-generation spintronic devices. This study was planned to investigate a potential DMS material based on Al2CO using first-principles methods. Al2CO is a direct band gap semiconductor with the energy gap of 1.77 eV in such a way that the conduction band minimum is composed of Al 3 s states, whereas the valence band maximum is contributed by p states of carbon and oxygen atoms. The phonon dispersion curves revealed the dynamical stability of Al2CO. The effect of 3d transition metal (TM) dopants doping into the Al2CO on the electronic and magnetic properties was systematically investigated. The cationic site near oxygen is found energetically feasible when compared with the site adjacent to a carbon atom in the host. The dopants produced spin-polarized gap states in an otherwise non-magnetic host. The hybridization of the p states of the host with the d states of dopant pointing to p-d exchange interactions is observed. The doping of Cr in the host exhibited half-metallic nature of the material. To check the magnetic ground state, double doping with the spin-flip configuration of the host was carried out. The results revealed that the entire 3d dopants prefer to adopt antiferromagnetic coupling in Al2CO. The finding demonstrates that Al2CO is a promising host material for creating new DMS to be used in spintronics.

keywords: Al2CO; Anti-ferromagnetism; Density functional theory; DMS; Ferrimagnetism; Spintronics