Below 280k the degenerated states were relieved and the electrons turned to the ordered states from the disordered , leading to the resistance increase suddenly and the transition from the cubic to the tetragonal structure 280k以后, mn原子軌道電子態(tài)的簡(jiǎn)并被解除,電子由無(wú)序向有序狀態(tài)轉(zhuǎn)變,電阻隨溫度的降低,急劇增加,材料結(jié)構(gòu)由立方相向四方相轉(zhuǎn)變。