TY - JOUR
T1 - Anisotropy of exchange stiffness based on atomic-scale magnetic properties in the rare-earth permanent magnet Nd2Fe14 B
AU - Toga, Yuta
AU - Nishino, Masamichi
AU - Miyashita, Seiji
AU - Miyake, Takashi
AU - Sakuma, Akimasa
N1 - Funding Information:
We acknowledge collaboration and fruitful discussions with Taro Fukazawa, Taichi Hinokihara, Shotaro Doi, Munehisa Matsumoto, Hisazumi Akai, and Satoshi Hirosawa. This work was partly supported by Elements Strategy Initiative Center for Magnetic Materials (ESICMM) under the auspices of MEXT; by MEXT as a social and scientific priority issue (Creation of New Functional Devices and High-Performance Materials to Support Next-Generation Industries; CDMSI) to be tackled by using a post-K computer. The computation was performed on Numerical Materials Simulator at NIMS; the facilities of the Supercomputer Center, the Institute for Solid State Physics, the University of Tokyo; the supercomputer of ACCMS, Kyoto University.
PY - 2018/8/17
Y1 - 2018/8/17
N2 - We examine the anisotropic properties of the exchange stiffness constant A for a rare-earth permanent magnet, Nd2Fe14B, by connecting analyses with two different scales of length, i.e., Monte Carlo (MC) method with an atomistic spin model and Landau-Lifshitz-Gilbert (LLG) equation with a continuous magnetic model. The atomistic MC simulations are performed on the spin model of Nd2Fe14B constructed from ab initio calculations, and the LLG micromagnetics simulations are performed with the parameters obtained by the MC simulations. We clarify that the amplitude and the thermal property of A depend on the orientation in the crystal, which are attributed to the layered structure of Nd atoms and weak exchange couplings between Nd and Fe atoms. We also confirm that the anisotropy of A significantly affects the threshold field for the magnetization reversal (coercivity) given by the depinning process.
AB - We examine the anisotropic properties of the exchange stiffness constant A for a rare-earth permanent magnet, Nd2Fe14B, by connecting analyses with two different scales of length, i.e., Monte Carlo (MC) method with an atomistic spin model and Landau-Lifshitz-Gilbert (LLG) equation with a continuous magnetic model. The atomistic MC simulations are performed on the spin model of Nd2Fe14B constructed from ab initio calculations, and the LLG micromagnetics simulations are performed with the parameters obtained by the MC simulations. We clarify that the amplitude and the thermal property of A depend on the orientation in the crystal, which are attributed to the layered structure of Nd atoms and weak exchange couplings between Nd and Fe atoms. We also confirm that the anisotropy of A significantly affects the threshold field for the magnetization reversal (coercivity) given by the depinning process.
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U2 - 10.1103/PhysRevB.98.054418
DO - 10.1103/PhysRevB.98.054418
M3 - Article
AN - SCOPUS:85051768681
VL - 98
JO - Physical Review B
JF - Physical Review B
SN - 2469-9950
IS - 5
M1 - 054418
ER -