非磁性掺杂下的铁磁/反铁磁系统中的交换偏置和矫顽场

采用Monte Carlo方法,分别讨论了在铁磁/反铁磁双层膜和铁磁/反铁磁单层混合膜中,掺入非磁性物质后,掺杂浓度对交换偏置以及矫顽场的影响.计算结果表明:随着掺杂浓度的增大,双层膜和单层膜交换偏置都有先增大后减小的现象,而其矫顽场则先减小后增大.在相同掺杂浓度下,对随机掺杂和规则掺杂两种不同掺杂方式的结果比较发现:铁磁/反铁磁双层膜中,规则掺杂下产生的交换偏置和矫顽场都得到了增强;对于单层混合膜,随机掺杂下的交换偏置更强,规则掺杂下的矫顽场更大.研究发现对于双层膜规则掺杂可明显地导致其磁滞回线的不对称性,说明铁磁/反铁磁系统中磁滞回线的不对称性与界面自旋微结构密切相关.

Exchange Bias and Coercivity in Nonmagnetic Doped Ferromagnetic/Antiferromagnetic (FM/AFM) Systems

The exchange bias and coercivity of FM/AFM bilayers and FM/AFM mixed monolayers with nonmagnetic dilution are studied in a Monte Carlo model.It shows that the exchange bias increases and then decreases with the increasing of dilution concentration while the coercivity decreases and then increases. With the same dilution concentration, both the exchange bias and the coercivity of the regular dilution are stonger than those of random dilution in FM/AFM bilayers.But in the mixed monolayer,the exchange bias of regular dilution is weaker than that of random dilution while the coercivity becomes stronger.Regular dilution results asymmetry in the hysteresis loops distinctly.It shows that the asymmetry of hysteresis loops in FM/AFM systems depends on the interface microstructure.