Temperature dependence and magnetic field dependence of magnetization. a Temperature dependence of the remnant magnetization M
r for samples A-D. M
r remains over zero even when the temperature reaches 340 and 350 K for samples B and D, respectively. b The magnetic field dependence of magnetization for MnAs grown on GaAs (110) and GaAs (001) at 300 K, under a magnetic field applied along the easy axis of magnetization.