Room Temperature Ferromagnetic Dilute Magnetic Semiconductor Zn_(0.95)Co_(0.05)O

摘要

Dilute magnetic semiconductors (DMSs) are semiconductors doped with magnetic elements, and DMS materials development is needed for the realization of spintronics devices. However, the origin of the contributions to the ferromagnetism in group II-VI DMS is still under debate. In this paper, we report on our study of ZnO thin films doped with transitional metal cobalt and ZnO thin films embedded with cobalt nanodots, fabricated through the use of Pulsed Laser Deposition technique. Different M-H curves were observed from SQUID measurements for the two systems prepared at 5 X 10~(-7) oxygen partial pressure, which shows that the contribution of room temperature ferromagnetism (RTFM) in our dilute magnetic semiconductor system is not mainly due to the metallic cobalt nanoclusters. Instead, oxygen vacancies or zinc interstitials would be the more likely factors that contribute to the RTFM in our DMS system. XRD and TEM were also used to characterize the structure of these two systems.