Magnetic Anisotropy of [Formula Omitted]-MnAl Thin Films

The [Formula Omitted]-MnAl alloy exhibits a high magnetic anisotropy energy despite the fact that both Mn and Al elements possess a low spin-orbit coupling constant. To understand the magnetic anisotropy mechanism, a systematic experimental study of the correlation between the magnetic anisotropy constant and the saturation magnetization of the [Formula Omitted]-phase MnAl thin films has been carried out. A torque measurement has been conducted to determine a uniaxial magnetic anisotropy constant [Formula Omitted] at various temperatures from 4 to 400 K. It is found that [Formula Omitted] is linearly dependent on saturation magnetization [Formula Omitted] over the temperature range from 4 to 400 K. This result is at variance with the theoretical predictions.