Kittilstved Kevin R, Schwartz Dana A, Tuan Allan C, Heald Steve M, Chambers Scott A, Gamelin Daniel R
Department of Chemistry, University of Washington, Seattle, Washington, 98195, USA.
Phys Rev Lett. 2006 Jul 21;97(3):037203. doi: 10.1103/PhysRevLett.97.037203. Epub 2006 Jul 19.
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.
通过对浅施主间隙锌进行可控引入和去除，验证了钴掺杂氧化锌（Co2+: ZnO）中高居里温度铁磁性由电荷载流子介导的假设。利用化学气相沉积生长的取向外延Co2+: ZnO薄膜，动力学测量表明铁磁性的氧化猝灭与间隙锌的扩散和氧化之间存在直接关联。这些结果表明Co2+: ZnO铁磁性所涉及的一个关键参数可进行可控的系统变化，并且在此过程中明确揭示这种铁磁性依赖于电荷载流子。文中还讨论了Co2+: ZnO中缺陷束缚载流子和自由载流子之间的区别。
