Abstract Motivated by the insufficient understanding of the drastic effects of the disordered interfacial phases at the interface in F/AF bilayers on the exchange bias properties, we consider a realistic model for F/AF nanodots which accounts for roughness at the interface, grain boundaries (GB) and magnetic frustration in the AF layer. Then, we investigate the effect of the magnetic disorder at the F/AF interface on the exchange field by means of Monte Carlo simulations. First, using a simplified model based on a perfect crystal structure (without GB) and with an ideal interface, our results indicate that non-collinear ordered magnetic configuration at the F/AF interface (due to frustration) causes a small decrease of the exchange field (about few dozen percent). Including GB in the model, we show that this kind of structural disorder produces disordered magnetic configurations with domains at the F/AF interface. This magnetic disorder does not lead to a decrease of the exchange field compared to the perfect crystal but makes the AF layer more stable. Our study also reveals that adding roughness in the form of a percentage of mixed F and AF moments in the interfacial layer results in a more significant decrease of the exchange field (two orders of magnitude) leading to values which are comparable to experimental values.

中文翻译：

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AF 层中晶界、界面粗糙度和非共线磁构型对 F/AF 纳米点交换偏置特性的影响：数值研究

摘要 由于对 F/AF 双层界面处的无序界面相对交换偏置特性的剧烈影响了解不足，我们考虑了 F/AF 纳米点的现实模型，该模型考虑了界面、晶界处的粗糙度（ GB) 和 AF 层中的磁挫败。然后，我们通过蒙特卡罗模拟研究了 F/AF 界面处的磁无序对交换场的影响。首先，使用基于完美晶体结构（无 GB）和理想界面的简化模型，我们的结果表明 F/AF 界面处的非共线有序磁性配置（由于挫折）导致交换的小幅下降领域（大约百分之几十）。模型中包含GB，我们表明这种结构无序会在 F/AF 界面产生具有磁畴的无序磁构型。与完美晶体相比，这种磁性无序不会导致交换场的降低，但会使 AF 层更加稳定。我们的研究还表明，在界面层中以混合 F 和 AF 矩的百分比形式添加粗糙度会导致交换场（两个数量级）的更显着降低，从而导致与实验值相当的值。