Unusual magnetic hysteresis behavior of oxide spinel MnCo 2O 4

Abstract

Magnetic hysteresis behavior of the oxide spinel MnCo 2O 4 has been studied at different temperatures below its T c≈184 K. Normal hysteresis behavior is observed down to 130 K whereas below this temperature the initial magnetization curve, at higher magnetic fields, lies outside the main loop. No related anomaly is observed in the temperature variation of magnetization or coercivity. However, the anisotropy field overcomes the coercivity below 130 K. The unusual magnetic hysteresis behavior of MnCo 2O 4, at low temperatures, may be associated with irreversible domain wall movements due to the rearrangement of the valence electrons.