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)
       
Panel (a) is the room-temperature absorption spectra. Panels (b)–(d) are PL spectra of samples with different x values at x = 0.63, 0.61, 0.24. Here, α and hν represent the absorption coefficient and the energy of the incident photon, respectively.