Micro-Structure and Magnetic Properties of Perpendicular Magnetized Co-CoO Sputtered Films

Abstract

Electrical resistivity (ρ) of reactive RF sputtered CO-CoO films increases and the temperature coefficient of resistivity (TCR) decreases with the formation of CoO. For films of which saturation magnetization (M_s) is more than 670 emu/cm³, ρ decreases irreversibly above 370 K by deoxidization. For films of which Ms is less than 470 emu/cm³, ρ increases irreversibly above 420K. After the irreversible increase of ρ, coercivity (H_c) and rectangular ratio of hysteresis loop perpendicular to the film plane increase, and H_c parallel to the film plane decreases.