Origin and enhancement of hole-induced ferromagnetism in first-row d0 semiconductors.
The origin of ferromagnetism in d;{0} semiconductors is studied using first-principles methods with ZnO as a prototype material. We show that the presence of spontaneous magnetization in nitrides and oxides with sufficient holes is an intrinsic property of these first-row d;{0} semiconductors and can be attributed to the localized nature of the 2p states of O and N. We find that acceptor doping, especially doping at the anion site, can enhance the ferromagnetism with much smaller threshold hole concentrations. The quantum confinement effect also reduces the critical hole concentration to induce ferromagnetism in ZnO nanowires. The characteristic nonmonotonic spin couplings in these systems are explained in terms of the band coupling model.
Peng
Haowei
H
State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P. O. Box 912, Beijing 100083, People's Republic of China.
Xiang
H J
HJ
Wei
Su-Huai
SH
Li
Shu-Shen
SS
Xia
Jian-Bai
JB
Li
Jingbo
J