Magneto-optical properties of ZnO-based diluted magnetic semiconductors

Magnetic circular dichroism (MCD) spectra of Zn1-xTMxO (TM = Sc, Ti, V, Cr, Mn, Co, Ni, and Cu) films were measured to clarify their magneto-optical properties. Noticeable magneto-optical effect was not observed for Zn1-xScxO, Zn1-xTixO, Zn1-xVxO, and Zn1-xCrxO. On the contrary, Zn1-xMnxO, Zn1-xCoxO, Zn1-xNixO, and Zn1-xCuxO showed pronounced negative MCD peaks near 3.4 eV which correspond to the band gap of the host ZnO semiconductor. These results show that ZnO alloyed with Mn, Co, Ni, and Cu is a diluted magnetic semiconductor with strong exchange interaction between sp-band carriers and localized d electrons. (C) 2001 American Institute of Physics.