Room-temperature ferromagnetism induced by Cu vacancies in Cu x(Cu2O)1− x granular films
Xie Xin-Jiana), Li Hao-Bob), Wang Wei-Chaob), Lu Fengb), Yu Hong-Yunc), Wang Wei-Hua†b), Cheng Ya-Hui‡b), Zheng Rong-Kund), Liu Huib)
       
(a) The XPS data and the corresponding Gaussian fitting curves of metallic Cu and Cu+ of sample under oxygen flow rate of 3.4 sccm. (b) The atomic ratio of Cu x in Cu x Cu2O1− x under the different oxygen flow rates.