Ferromagnetism in 2p Light Element-Doped II-oxide and III-nitride Semiconductors

TL;DR

This study uses first-principle calculations to predict ferromagnetism in certain nonmagnetic light element-doped II-oxide and III-nitride semiconductors, proposing mechanisms to enhance magnetic properties for spintronic applications.

Contribution

It introduces a theoretical prediction of ferromagnetism in specific doped semiconductors and proposes a co-doping strategy to enhance magnetic coupling.

Findings

Nitrogen and carbon doping induce ferromagnetism in ZnO and AlN.

Ferromagnetism arises from p-d exchange-like p-p coupling interactions.

Co-doping with beryllium and nitrogen enhances ferromagnetic coupling.

Abstract

II-oxide and III-nitride semiconductors doped by nonmagnetic 2p light elements are investigated as potential dilute magnetic semiconductors (DMS). Based on our first-principle calculations, nitrogen doped ZnO, carbon doped ZnO, and carbon doped AlN are predicted to be ferromagnetic. The ferromagnetism of such DMS materials can be attributed to a p-d exchange-like p-p coupling interaction which is derived from the similar symmetry and wave function between the impurity (p-like t_2) and valence (p) states. We also propose a co-doping mechanism, using beryllium and nitrogen as dopants in ZnO, to enhance the ferromagnetic coupling and to increase the solubility and activity.