Band gap and function engineering for novel functional alloy semiconductors: Bloomed as magnetic properties at room temperature with α-(GaFe)_2O_3

摘要

Highly crystalline corundum structured α-(Ga_(0.42Fe_(0.58))_2O_3 alloy thin film showed magnetic properties at room temperature. Microstructure analysis of cross-sectional transmission electron microscope (TEM) observation and TEM energy dispersive X-ray spectroscopy measurement indicated that different crystal phase could not be detected as well as there is no remarkable phase separating area, that is, Fe and Ga ions are distributed uniformly in the film. Magnetic measurements were performed on α-(Ga_(0.42)Fe_(0.58))_2O_3 (x = 0.24, 0.44, 0.58, 1.00) alloy thin films at 110K. The induced magnetic moment per a Fe ion of α-(Ga_(0.42)Fe_(0.58))_2O_3 at 5000 Oe is about 6 times larger than α-Fe_2O_3 thin film. Compared to the α-Fe_2O_3 thin films, the value of coercivity is also about 6 times in α-(Ga_(0.42)Fe_(0.58))_2O_3, in contrast, there is no significant difference in value of coercivity of α-(Ga_(1-x)Fe_x)_2O_3 (x = 0.24, 0.44, 1.00) thin films. These means that the origin of magnetism is not the separation region of α-Fe_2O_3 in α-(Ga_(1-x)Fe_x)_2O_3 thin film.