INVESTIGATION OF THE STRUCTURAL PHASE TRANSITION OF MnBi AND MnBiAl FILMS

Structural phase transition of MnBi and MnBiAl films has been investigated in the tem-perature range of 30-400℃. The transition from low-temperature phase to high-temperature phase occurs in both the films, but the phase transitions appear at different temperatures. According to the measurement of Kerr rotation as a function of thermal annealing and the phase transition process, it is shown that the transition is irreversible for MnBi film and reversible for MnBiAl film under our experimental condition. For this reason, we speculate that the aluminum added in MnBi makes the bonding force of Mn atoms with their neighbors stronger, which may be the cause for the difference of the phase transition between MnBi and MnBiAl films.