First-principles study of the magnetic properties of Zn-doped SnO2

First-principle calculations were used to study the magnetic properties of Zn-doped SnO2. We first investigated the energy of formation for oxygen vacancies (VO), tin vacancies (VSn), interstitial oxygen (Oi), interstitial tin (Sni), Zn substitution of Sn (ZnSn), and Zn substitution of O (ZnO). We then studied ferromagnetic (FM) and antiferromagnetic (AFM) coupling in Zn-doped SnO2. The results show that the FM state has lower energy than the AFM state for all configurations, indicating that Zn-doped SnO2 has FM stability. This stability can be explained by interaction of the O 2p level. We also analyzed the impact of VO and VSn on FM coupling. VSn can enhance FM coupling, but VO is unfavorable for FM coupling.