The Electronic Structures and Magnetism in Al Doped 4H-SiC: The First-Principles Calculation

Abstract

In the field of a diluted magnetic semiconductor, a nontransition metal doped semiconductor or oxide is a way to avoid the ferromagnetic clusters of secondary phase. Since there is no d electron in such system, the origin of magnetism is a surprise. In this article, first-principles calculations were used to investigate the origin of magnetism in Al doped 4H-SiC. It is found that a hole was introduced into the SiC:Al system, which is located on one C atom adjacent to the Si vacancy. A neutral Si vacancy with a substituting Al lead to the formation of a net moment less than 1.0μB, while the Al itself has no contribution to the magnetic moment, but plays a key role to form them. The coupling between such local moments is paramagnetic.