# Fileset

[abstract.docx](https://mdr.nims.go.jp/filesets/cf8cdd63-10db-44c3-b10d-0cc425bb6a8b/download)

## Creator

[BOLYACHKIN Anton](https://orcid.org/0000-0003-0420-1806), [SEPEHRI AMIN Hossein](https://orcid.org/0000-0002-7856-7897), DENGINA Ekaterina, [KULESH Nikita](https://orcid.org/0000-0001-7046-2671), [TANG Xin](https://orcid.org/0000-0001-6762-6145), [TAKAHASHI Yukiko](https://orcid.org/0000-0001-9197-7236), [OHKUBO Tadakatsu](https://orcid.org/0000-0003-3548-1951), [HONO Kazuhiro](https://orcid.org/0000-0001-7367-0193)

## Rights

[In Copyright](http://rightsstatements.org/vocab/InC/1.0/)

## Other metadata

[Digital twins of magnetic materials: revealing microstructure-properties correlations](https://mdr.nims.go.jp/datasets/4b56377f-7f60-46e1-bb39-b56b41607ba0)

## Fulltext

Digital twins of magnetic materials:revealing microstructure-properties correlationsAnton Bolyachkin1,2, Hossein Sepehri-Amin1,3, Ekaterina Dengina1,3, Nikita Kulesh1,Xin Tang1,2, Yukiko Takahashi1, Tadakatsu Ohkubo1, and Kazuhiro Hono1,31 Research Center for Magnetic and Spintronic Materials, National Institute for Materials Science, Tsukuba, 305-0047, JapanEmail: bolyachkin.anton@nims.go.jp2 International Center for Young Scientists, National Institute for Materials Science,Tsukuba, 305-0047, Japan3 Graduate School of Science and Technology, University of Tsukuba,Tsukuba, 305-8573, JapanAbstractMagnetic materials are among the prime functional materials in establishing a carbon-neutral society. In particular, high-density magnetic recording media are required in data centers, while permanent magnets are essential components in motors of hybrid/electric vehicles and generators of wind turbines. It is important to improve the performance of such magnetic materials up to their practical limits through fine compositional and microstructural optimization. Micromagnetic simulations are usually incorporated to boost this optimization. These simulations are especially useful when a realistic model of the material can be constructed – a digital twin. Our recent achievements in developing such representative micromagnetic models will be presented in this report. First, a TEM image-based finite element model of FePt granular media allowed us to elucidate the effect of nanodefects on magnetic properties and to realize the micromagnetic approximation of hysteresis loops assisted by machine learning [1,2]. Second, the similar TEM-based approach was used to explain the suppressed coercivity in SmFe12-based anisotropic thin films and to guide toward its remarkable enhancement [3]. Finally, the most challenging large-scale finite element model was constructed for Nd-Fe-B hot-deformed magnets based on the FIB-SEM tomographic data obtained for a real sample. With this model, we were able to reproduce the experimental coercivity and to explain its microstructural origins. Thus, the combination of advanced microstructure characterization techniques, state-of-the-art data processing algorithms including machine learning, and GPU-accelerated micromagnetic simulations can bring a new horizon in the design of high-performance magnetic materials.[1] A. Bolyachkin, H. Sepehri-Amin, I. Suzuki, H. Tajiri, Y.K. Takahashi, K. Srinivasan, H. Ho, H. Yuan, T. Seki, A. Ajan, and K. Hono, Acta Mater. 227, 117744 (2022).[2] E. Dengina, A. Bolyachkin, H. Sepehri-Amin, and K. Hono, Scripta Mater. 218, 114797 (2022).[3] A. Bolyachkin, H. Sepehri-Amin, M. Kambayashi, Y. Mori, T. Ohkubo, Y.K. Takahashi, T. Shima, and K. Hono, Acta Mater. 227, 117716 (2022).Keywords: micromagnetic simulations, magnetic recording, permanent magnets