标题：Oxygen vacancies modulated coexistence of antiferromagnetism and ferromagnetism in Zn x Co 1−x O single crystal epitaxial films
作者：Cai L.; Cao Q.; Zhang K.; Fu M.; Liu J.; Huang Q.; Tian Y.; Liu G.;等 更多 作者机构：[Cai, L] School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China;[ Cao, Q] Spintronics Institute, Univ 更多
通讯作者地址：[Yan, S] School of Physics, State Key Laboratory of Crystal Materials, Shandong UniversityChina;
来源：Journal of Magnetism and Magnetic Materials
关键词：Antiferromagnetic material; Epitaxial film; Exchange bias; Oxygen vacancy
摘要：Recently antiferromagnetic materials become very attractive due to their new applications in spintronic devices. High-quality single crystal epitaxial Zn x Co 1−x O (1 1 1) thin films were grown by co-evaporating Zn and Co and simultaneously oxidizing in oxygen plasma. It is found that the exchange bias fields of Co/as-prepared Zn x Co 1−x O bilayers decrease with increasing Zn composition. When as-prepared Zn x Co 1−x O layer was annealed in oxygen plasma to remove oxygen vacancies, the exchange bias field of Co/oxygen-plasma-annealed Zn x Co 1−x O bilayers can be further enhanced. Moreover, a weak ferromagnetism was observed at 300 K in the as-prepared antiferromagnetic Zn x Co 1−x O film with oxygen vacancies, but it did not exist in oxygen-plasma-annealed Zn x Co 1−x O film. This indicates that oxygen vacancies can simultaneously weaken the antiferromagnetism but enhance the ferromagnetism of Zn x Co 1−x O layer. Therefore, we offer a method of manipulating the antiferromagnetism of Zn x Co 1−x O films by changing Zn composition and oxygen vacancies, which is useful for designing antiferromagnetic spintronic devices. © 2018 Elsevier B.V.