柔性衬底上铁磁/反铁磁双层膜的磁性研究

Magnetic properties of ferromagnetic/antiferromagnetic bilayers on flexible substrates

目的:研究溅射在聚酰亚胺PI柔性衬底上铁磁/反铁磁Ni_(81)Fe_(19)/Fe_(50)Mn_(50)双层膜的交换偏置效应。方法:采用超高真空磁控溅射法在柔性衬底PI上制备Ni_(81)Fe_(19)/Fe_(50)Mn_(50)系列双层膜,将其退火后使用振动样品磁强计测试样品的场冷磁滞回线。结果:铁磁层厚度的增大使得柔性衬底上双层膜交换偏置场和矫顽力几乎呈现线性减小;当反铁磁层较薄时,未出现交换偏置,到达一定厚度后交换偏置场出现先增大后稳定的现象;当冷却场为零时未产生交换偏置场,随着冷却场的增大,交换偏置场在冷却场1000 Oe时达到最大值,随后冷却场继续增大,交换偏置场却出现下降的趋势。结论:柔性衬底上和硅片上生长的铁磁/反铁磁双层膜交换偏置场大小基本相同,柔性衬底可以显著增大薄膜的矫顽力。

Aims:The purpose of this study is to investigate the exchange bias effect of Ni_(81)Fe_(19)/Fe_(50)Mn_(50) bilayers sputtering on polyimide PI flexible substrates.Methods:The Ni_(81)Fe_(19)/Fe_(50)Mn_(50) series bilayers was prepared by the ultra-high vacuum magnetron sputtering method on flexible substrate PI;and the hysteresis loop of the sample was tested by vibration sample magnetometers after annealing.Results:We found that the exchange bias effect on flexible substrates was almost the same as that on rigid substrates.With the increase of the ferromagnetic layer thickness,the exchange bias and coercivity of the bilayers under the flexible substrate decreased almost linearly.When the antiferromagnetic layer was relatively thin,there was no exchange bias.When the thickness of the antiferromagnetic layer reached a certain thickness,the exchange bias of the double layer increased first and then stabilized.When the cooling field was zero,there was no exchange bias.However,as the cooling field increased,the exchange bias reached its maximum value at 1000 Oe.But then the cooling field continued to increase;and the exchange bias showed a downward trend.Conclusions:The exchange bias fields of ferromagnetic/antiferromagnetic bilayers on flexible substrates and Si substrates are little different.But flexible substrate makes coercivity increase a lot.