High coercivity in large exchange-bias Co/CoO-MgO nano-granular films*
Ge Chuan-Nana),b), Wan Xian-Ganga)†, Eric Pellegrinc), Hu Zhi-Weid), Wen-I Liange), Michael Brunsf), Zou Wen-Qina), Du You-Weia)
       
(a) XPS spectra of Co75/(CoO)15-(MgO)10 (top) and Co22/(CoO)24-(MgO)15 (bottom). (b) Experimental μ + and μ − spectra of Co75/(CoO)15-(MgO)10. (c) Simulated μ + and μ − spectra generated from a superposition of calculated data for CoO and experimental data for Co metal. (d) Comparison of the experimental XMCD spectrum of Co75/(CoO)15-(MgO)10, and (e) the simulated XMCD spectrum by a superposition of the calculated XMCD from the CoO shell (the black line shown in panel (e)) and experimental Co metal XMCD (the magenta line shown in panel (e)).