| AVS 54th International Symposium | |
| Magnetic Interfaces and Nanostructures | Thursday Sessions |
| Session MI-ThA |
| Session: | Magnetic Semiconductors II |
| Presenter: | C.A. Johnson, University of Washington |
| Authors: | C.A. Johnson, University of Washington D.R. Gamelin, University of Washington |
| Correspondent: | Click to Email |
Demonstration of reproducible intrinsic high-temperature ferromagnetism in diluted magnetic semiconductors (DMSs) is an important step toward their use in devices. Recently it has become apparent that understanding the defects in Co2+:ZnO is paramount to understanding the microscopic origins of its ferromagnetism. We will describe that Co2+:ZnO films can be made ferromagnetic by annealing under Zn vapor to create the Zni lattice defect.1 Oxidation of the Zn-treated Co2+:ZnO films at elevated temperatures results in a controlled quenching of the ferromagnetism as the Zni migrates out of the lattice and is oxidized.2 These changes can be followed kinetically using both magnetic measurements and magnetic circular dichroism spectroscopy. These results demonstrate that ferromagnetism of Co2+:ZnO thin films can be controlled by controlling Zni concentrations and provide new insights into the microscopic origins of this interesting magnetism.
1 Schwartz, D.A. and D.R. Gamelin, Adv Mat, 2004. 16 2115-2118.
2 Kittilstved, K.R., Schwartz, D.A., Tuan, A.C., Heald, S.M., Chambers, S.A., Gamelin, D.R., Phys Rev Let, 2006. 97 0372203.