论文标题
来自带有Neel表面各向异性的球形纳米颗粒的磁中子散射:原子模拟
Magnetic neutron scattering from spherical nanoparticles with Neel surface anisotropy: Atomistic simulations
论文作者
论文摘要
我们考虑了随机取向非相互作用的球形纳米磁体的稀释合奏,并通过数值求解Landau-Lifshitz方程来研究其磁化结构并随之而来的中子散射响应。考虑到各向同性交换相互作用,外部磁场,颗粒芯的单轴磁各向异性,尤其是尼尔表面各向异性,我们从获得的平衡旋转结构中计算了磁性小角度中子中子散射横截面和成对距离分布函数。将数值结果与均匀磁性颗粒的众所周知的分析表达进行了比较,并为实验者提供了指导。此外,对粒度分布函数的效果进行了建模。
We consider a dilute ensemble of randomly-oriented noninteracting spherical nanomagnets and investigate its magnetization structure and ensuing neutron-scattering response by numerically solving the Landau-Lifshitz equation. Taking into account the isotropic exchange interaction, an external magnetic field, a uniaxial magnetic anisotropy for the particle core, and in particular the Neel surface anisotropy, we compute the magnetic small-angle neutron scattering cross section and pair-distance distribution function from the obtained equilibrium spin structures. The numerical results are compared to the well-known analytical expressions for uniformly magnetized particles and provide guidance to the experimentalist. Moreover, the effect of a particle-size distribution function is modeled.