The discovery of reversible 300 K ferromagnetic ordering in a diluted magnetic semiconductor is reported. Switching of room-temperature ferromagnetism between "on" and "off" states is achieved in Co2+:ZnO by lattice incorporation and removal of the native n-type defect, interstitial Zn. Spectroscopic and magnetic data implicate a double-exchange mechanism for ferromagnetism. These results demonstrate for the first time reversible room-temperature ferromagnetic ordering in a diluted magnetic semiconductor, and present new opportunities for integrating magnetism and conductivity in semiconductor sensor or spin-based electronics devices.
@article{arxiv.cond-mat/0404518,
title = {Reversible 300K Ferromagnetic Ordering in a Diluted Magnetic Semiconductor},
author = {Dana A. Schwartz and Daniel R. Gamelin},
journal= {arXiv preprint arXiv:cond-mat/0404518},
year = {2007}
}