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)
       
Magnetic hysteresis loops of (a) the Co56/(CoO)32-(MgO)12 sample and (b) the Co75/(CoO)15-(MgO)10 sample measured at 2 K after cooling the samples in zero field (ZFC) or in a 5 kOe cooling field (FC), respectively. The inserts show the details of the hysteresis loops.