Fabrication of Co/CoO Exchange Bias System by Ion Implantation and Its Magnetic Properties

We use ion implantation as a new approach to build an anti-ferromagnetic (AFM) cluster embedded exchange bias (EB) system. Co film with thickness of 130nm is deposited on the Si (111) substrate using magnetron sputtering, 60keV O⁺ is chosen to implanted into the Co film to form CoO AFM clusters coupling with Co matrix at the interface. By measuring the hysteresis loop after field-cooling, significant shifts of loop along the applied field are confirmed. When increasing the implantation dose to 2×10¹⁷/cm² and annealed samples in N₂ atmosphere, we obtain the highest H_EB to 458Oe.