Monte Carlo Simulation of the FM Layer Thickness Influence on the Exchange Bias in FM/AFM Bilayers
Monte Carlo Simulation of the FM Layer Thickness Influence on the Exchange Bias in FM/AFM Bilayers
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DOI：
10.1109/tmag.2009.2031080
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发表时间：
2009-11-01
影响因子：
2.1
通讯作者：
Riano-Rojas, J. C.
中科院分区：
文献类型：
--
作者：
Restrepo-Parra, E.;Restrepo, J.;Riano-Rojas, J. C.
采用经典的海森堡模型和Metropolis算法对铁磁/反铁磁(FM/AFM)双层膜的交换偏置特性进行了蒙特卡罗模拟研究。在我们的模型中，考虑了最近邻交换作用、两种不同的界面耦合、磁晶各向异性和塞曼项等多种贡献。我们的研究重点是FM和AFM层厚度(d(F)和d(A))对磁滞回线的影响，特别是交换偏置场(H-EB)和矫顽力(H-c)。结果表明，对交换偏置现象的影响可以忽略不计，而对(H-EB)和H-c有重要影响。这种行为符合文献中报道的几个模型和结果。具体地说，我们的模型允许推断交换偏置场与FM层厚度成正比1/(d(F))(M)的依赖关系，其表征为指数m=0.71+/-0.11。另一方面，当热涨落变得相关时，矫顽力随FM层厚度的增加而呈幂函数增加。为了完备性，最后给出并讨论了滞回特性的热稳定性。
A Monte Carlo simulation study of the exchange bias properties in ferromagnetic/antiferromagnetic (FM/AFM) bilayers by using a classical Heisenberg model and the Metropolis algorithm is addressed. In our model several contributions including nearest neighbors exchange interactions, two different interface couplings, magnetocrystalline anisotropy, and a Zeeman term were considered. Our study focuses on the influence of FM and AFM layer thicknesses (d(F) and d(A)) on hysteresis loops, particularly exchange bias field (H-EB) and coercive force (H-c). Results reveal that the influence of on the exchange bias phenomenon is negligible, while produces an important effect on (H-EB) and H-c. Such behaviors agree with several models and results reported in the literature. Concretely, our model allows inferring a dependence of the exchange bias field with the FM layer thickness proportional to 1/(d(F))(m) characterized by an exponent m = 0.71 +/- 0.11. On the other hand, coercive force exhibits a power law increase with the FM layer thickness when thermal fluctuations become relevant. For completeness, thermal stability of the hysteretic properties is finally presented and discussed.