ABSTRACT
290Spintronics device is a future device using spin rather than charge to realize device functions, having advantage over traditional devices, such as low power, high speed, and flow-a-spin current without dissipation. Diluted magnetic semiconductor (DMS) is one of the promising materials for the applications of spintronics device since it has both spin and semiconductor behavior, easily integrated to current semiconductor technology. Mn-doped GaAs is one of the model systems for Ill-V-based diluted magnetic semiconductor. However, its low Curie temperature makes it unable for practical applications. Oxide semiconductor such as ZnO has been predicted to be one of the promising semiconductor host for DMSs with high Curie temperature. The following research on oxide semiconductor (i.e., ZnO, TiO2, SnO2, In2O3)-based DMSs have shown that high Curie temperature has been observed in many systems. However, there are disputes on the origin of the ferromagnetism. In Chapter 6, oxide-based DMSs have been introduced. In this chapter, we will introduce the study of magnetism in oxide-based DMSs using first principles calculations. First, we introduce the basics for first principles calculations. Then, we introduce the study of different oxidebased systems by first principles calculations.
