AFM纳米颗粒镶嵌于FM基体交换偏置效应及其机制研究

拟采用磁过滤真空阴极电弧离子镀以及金属真空弧（MEVVA）离子注入复合技术，制备反铁磁性(AFM)Cr纳米颗粒嵌入铁磁性(FM)Fe基体磁性纳米颗粒膜。通过研究制备工艺对磁性纳米颗粒膜中AFM颗粒大小、浓度及尺寸分布，以及交换偏置、矫顽力和剩磁等磁性性能的影响，探索最佳制备条件以获得交换偏置明显的AFM纳米颗粒嵌入FM基体磁性纳米颗粒膜材料；通过改进"York协议"磁性测量方法，使之适用于磁性纳米颗粒膜交换偏置体系；并采用改进的"York协议"磁性测量方法对磁性纳米颗粒膜交换偏置体系的反铁磁各向异性、交换偏置截止温度以及界面效应等对交换偏置影响进行研究，建立交换偏置模型来解释及准确预测体系的交换偏置。通过对磁性纳米颗粒膜交换偏置体系AFM及FM磁畴在外场下的演化以及磁学性质的研究，辅助蒙特卡罗模拟方法，从理论上深入探索AFM纳米颗粒嵌入FM基体磁性颗粒膜交换偏置效应的微观机制。

A nanogranular film consisting of antiferromagnetic (AFM) Cr nanoparticles embedded in ferromagnetic (FM) Fe matrix is prepared by using the filtered cathodic vacuum arc deposition method and metal vapor vacuum arc (MEVVA) ion implantation. The effects of preparation conditions on particle size, concentration, and distribution of AFM nanoparticle and magnetic properties such as exchange bias, coercivity and remanence of nanogranular films will be investigated. The suitable condition to get large exchange bias field for the nanogranular film is obtained. The "York Protocol" for measurement of exchange bias is applied to the nanogranular system consisting AFM nanoparticles embedded in FM matrix. And the modified "York Protocol" are used to the measurements of blocking temperatures, anisotropy constant of AFM and effects of both in the bulk of AFM and at the interface. Based on the modified "York Protocol", the exchange bias model is obtained, which is able to predict the value of exchange bias in the real system. Mechanism of exchange bias for isolated AFM nanoparticles embedded in FM matrix is obtained according to the evolution of the domains of AFM and FM under the magnetic field and the Monte Carlo study.