Magnetoresistance Effect in Antiferromagnet-Based Nanogranular Films

Magnetic and magneto-transport properties of nano-structured CoO-Ag granular films are reported. Apparent magnetization hysteresis is observed for low CoO contents and becomes weaker with increasing CoO content. Magnetoresistance (MR) ratio has a maximal value near 84vol% CoO and is reduced at low CoO contents. It decreases with increasing temperature and disappears near the Néel temperature of CoO. The uncompensated magnetic moments of CoO particles have been clearly demonstrated by MR effect.