Abstract:

A series of Zn_1-xCo_xO、Ti_1-xCo_xO₂、(In_1-xCo_x)2O3magnetic semiconductor films with high concentration of the transitional metal Co element (concentrated magnetic semiconductor) were prepared by sputtering machine. The super performance of the materials, such as the high Currie temperature above room temperature, high spin polarization ratio, and large magneto-optical Kerr effect were found in the concentrated magnetic semiconductor films. The electric transport properties were also systematically studied by experiments and theories, and a spin dependent variable range hopping model was proposed. The concentrated magnetic semiconductors are different from the conventional dilute magnetic semiconductors, and they may become good spin injection source and new transparent magneto-optical material.

Key words: magnetic semiconductor; ferromagnetism; spin-polarized transport