退火对IrMn基磁隧道结多层膜热稳定性的影响

摘要

The magnetic tunnel junction with a structure of IrMn/CoFe/AlOx/CoFe is deposited by magnetron sputtering and annealed at different temperatures in a magnetic field of parallel to the orienting field.Vibrating sample magnetometer is used to record the magnetic hysteresis loop at room temperature,and scanning probe microscope is used to record the interface morphology.The influence of annealing on thermal stability of the magnetic tunnel junction is investigated by holding the film in its negative saturation field.After annealing,the exchange bias increases due to the enhancement of unidirectional anisotropy of antiferromagnetic layer.The recoil loop of the pinned ferromagnetic layer shifts towards the positive field,and the exchange bias field decreases monotonically,with the film held in a negative saturation field,whereas annealing reduces the reduction speed of Hex.%采用磁控溅射方法制备了结构为IrMn/CoFe/AlOx/CoFe的磁性隧道结多层膜,样品置于真空磁场中进行退火处理.将在不同温度退火的磁隧道结结构多层膜置于负饱和场中等待,研究退火温度对样品热稳定性的影响.结果表明：退火提高了多层膜反铁磁层的单轴各向异性能,增加了样品的交换偏置;随着负饱和场等待时间的延长,被钉扎层的磁滞回线向正场偏移,交换偏置单调减小,但退火减弱了这种趋势.