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arXiv · 2007.14101

Data Assimilation Method for Experimental and First-Principles Data: Finite-Temperature Magnetization of (Nd,Pr,La,Ce)$_{2}$(Fe,Co,Ni)$_{14}$B

Yosuke Harashima·Keiichi Tamai·Shotaro Doi·Munehisa Matsumoto·Hisazumi Akai·Naoki Kawashima·Masaaki Ito·Noritsugu Sakuma·Akira Kato·Tetsuya Shoji·Takashi Miyake
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Abstract

We propose a data-assimilation method for evaluating the finite-temperature magnetization of a permanent magnet over a high-dimensional composition space. Based on a general framework for constructing a predictor from two data sets including missing values, a practical scheme for magnetic materials is formulated in which a small number of experimental data in limited composition space are integrated with a larger number of first-principles calculation data. We apply the scheme to (Nd$_{1-α-β-γ}$Pr$_α$La$_β$Ce$_γ$)$_{2}$(Fe$_{1-δ-ζ}$Co$_δ$Ni$_ζ$)$_{14}$B. The magnetization in the whole $(α, β, γ, δ, ζ)$ space at arbitrary temperature is obtained. It is shown that the Co doping does not enhance the magnetization at low temperatures, whereas the magnetization increases with increasing $δ$ above 320 K.

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Yosuke Harashima, Keiichi Tamai, Shotaro Doi, Munehisa Matsumoto, Hisazumi Akai, Naoki Kawashima, Masaaki Ito, Noritsugu Sakuma, Akira Kato, Tetsuya Shoji, Takashi Miyake. 2020-07-28. Data Assimilation Method for Experimental and First-Principles Data: Finite-Temperature Magnetization of (Nd,Pr,La,Ce)$_{2}$(Fe,Co,Ni)$_{14}$B. https://doi.org/10.1103/physrevmaterials.5.013806

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