title: Direct kinetic correlation of carriers and ferromagnetism in Co2+: ZnO.
abstract: The hypothesis that high-Curie-temperature ferromagnetism in cobalt-doped ZnO (Co2+: ZnO) is mediated by charge carriers was tested by controlled introduction and removal of the shallow donor interstitial zinc. Using oriented epitaxial Co2+: ZnO films grown by chemical vapor deposition, kinetics measurements demonstrate a direct correlation between the oxidative quenching of ferromagnetism and the diffusion and oxidation of interstitial zinc. These results demonstrate controlled systematic variation of a key parameter involved in the ferromagnetism of Co2+: ZnO and, in the process, unambiguously reveal this ferromagnetism to be dependent upon charge carriers. The distinction between defect-bound and free carriers in Co2+: ZnO is discussed.
authors.affiliation: Department of Chemistry, University of Washington, Seattle, Washington, 98195, USA.
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Kittilstved
authors.forename: Dana A
authors.initials: DA
authors.lastname: Schwartz
authors.forename: Allan C
authors.initials: AC
authors.lastname: Tuan
authors.forename: Steve M
authors.initials: SM
authors.lastname: Heald
authors.forename: Scott A
authors.initials: SA
authors.lastname: Chambers
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Gamelin