Experimental SANS studies and micromagnetic simulations of neutron scattering on polycrystalline magnetic materials

多晶磁性材料上中子散射的实验 SANS 研究和微磁模拟

• 批准号: 106658842
• 负责人: Privatdozent Dr. Dmitry Berkov
• 金额: --
• 依托单位: Laboratory for the Physics of Advanced Materials
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/106658842?language=en
• 关键词: Experimental; SANS; studies; micromagnetic; simulations

We intend to investigate the magnetic microstructure of multi-phase nanocomposites by combining magnetic-field dependent small-angle neutron scattering (SANS) measurements with full-scale micromagnetic simulations. Motivated by the recent observation of a novel angular anisotropy in the magnetic SANS cross section of the Fe-based two-phase alloy Nanoperm, we propose to develop a new micromagnetic method which will enable us to calculate the magnetization distribution and corresponding magnetic SANS cross section of a representative 3D nanocrystalline system. From an experimental point of view, the SANS experiments allow us to probe the spin microstructure in the sample volume and on a length scale of a few up to a few hundreds of nanometers. The computational part of the project will help us in identifying those parts of the nanocomposite parameter space where the most interesting physics is hidden. For this purpose simulations will be performed for various values of the external magnetic field (as SANS measurements) and for various microstructural and magnetic parameters of the composites (e.g., particle volume fraction, particle size, particle-size distribution, contrast in magnetization magnitude between the phases). The project will provide fundamental contributions to our basic understanding of magnetic neutron scattering from nanomagnets and improves our knowledge on the interplay between their nuclear microstructure and magnetic properties.

我们打算通过结合磁场相关的小角中子散射(SANS)测量和全尺寸的微磁模拟来研究多相纳米复合材料的磁性微结构。基于最近在铁基两相合金纳米晶的磁扫描截面上观察到的一种新的角各向异性，我们提出了一种新的微磁学方法，它将使我们能够计算一个典型的三维纳米晶系统的磁化强度分布和相应的磁扫描截面。从实验的角度来看，SANS实验使我们能够探测样本体积中的自旋微结构，并在几到几百纳米的长度范围内进行探测。该项目的计算部分将帮助我们确定纳米复合参数空间中隐藏着最有趣的物理学的部分。为此，将对外部磁场的各种值(如SANS测量)以及复合材料的各种微观结构和磁性参数(例如，颗粒体积分数、颗粒尺寸、颗粒尺寸分布、相之间磁化强度的对比度)进行模拟。该项目将为我们对纳米磁铁的磁中子散射的基本理解提供基本的贡献，并提高我们对纳米磁铁的核微结构和磁性之间相互作用的认识。

项目成果

Comment on "origin of surface canting within Fe(3)O(4) nanoparticles".

对“Fe(3)O(4) 纳米颗粒内表面倾斜的起源”的评论

• DOI: 10.1103/physrevlett.114.149701
• 发表时间: 2015
• 期刊: Physical review letters
• 影响因子: 8.6
• 作者: Michels;Honecker;Erokhin;Berkov
• 通讯作者: Berkov

Dipolar spin-misalignment correlations in inhomogeneous magnets: Comparison between neutron scattering and micromagnetic approaches

• DOI: 10.1103/physrevb.92.014427
• 发表时间: 2015-07-30
• 期刊: PHYSICAL REVIEW B
• 影响因子: 3.7
• 作者: Erokhin, Sergey;Berkov, Dmitry;Michels, Andreas
• 通讯作者: Michels, Andreas

Optimization of Nanocomposite Materials for Permanent Magnets: Micromagnetic Simulations of the Effects of Intergrain Exchange and the Shapes of Hard Grains

• DOI: 10.1103/physrevapplied.7.014011
• 发表时间: 2017-01
• 期刊: Physical review applied
• 影响因子: 4.6
• 作者: S. Erokhin;D. Berkov