Zobrazeno 1 - 10
of 72
pro vyhledávání: '"Harashima, Yosuke"'
Autor:
Harashima, Yosuke, Miyake, Takashi, Baba, Ryuto, Takayama, Tomoaki, Takasuka, Shogo, Shigeta, Yasuteru, Yamaguchi, Yuichi, Kudo, Akihiko, Fujii, Mikiya
This study proposes a materials search method combining a data assimilation technique based on a multivariate Gaussian distribution with Bayesian optimization. The efficiency of the optimization using this method was demonstrated using a model functi
Externí odkaz:
http://arxiv.org/abs/2408.08539
Autor:
Harashima, Yosuke, Koga, Hiroaki, Ni, Zeyuan, Yonehara, Takehiro, Katouda, Michio, Notake, Akira, Matsui, Hidefumi, Moriya, Tsuyoshi, Si, Mrinal Kanti, Hasunuma, Ryu, Uedono, Akira, Shigeta, Yasuteru
The structural stabilities of the monoclinic and tetragonal phases of Si-doped HfO$_{2}$ at finite temperatures were analyzed using a computational scheme to assess the effects of impurity doping. The finite temperature effects considered in this wor
Externí odkaz:
http://arxiv.org/abs/2303.14891
The stability of ($R$, Zr)(Fe, Co, Ti)$_{12}$ with a ThMn$_{12}$ structure is investigated using first-principles calculations. We consider energetic competition with multiple phases that have the Th$_2$Zn$_{17}$ structure and the unary phases of $R$
Externí odkaz:
http://arxiv.org/abs/2112.09297
We investigate the effects of various dopants (M = K--Br) on the Curie temperature of the magnetic compound NdFe12 through first-principles calculations. Analysis by the Korringa--Kohn--Rostoker method with the coherent potential approximation reveal
Externí odkaz:
http://arxiv.org/abs/2108.07452
Publikováno v:
Phys. Rev. B 103, 024418 (2021)
We theoretically investigate spin-wave dispersion in rare-earth magnet compounds by using first-principles calculations and a method we call the reciprocal-space algorithm (RSA). The value of the calculated exchange stiffness for Nd$_2$Fe$_{14}$B is
Externí odkaz:
http://arxiv.org/abs/2010.16022
Publikováno v:
J. Phys. Soc. Jpn. 90, 094001 (2021)
Machine learning has recently been applied to many problems in condensed matter physics. A common point of many proposals is to save computational cost by training the machine with data from a simple example and then using the machine to make predict
Externí odkaz:
http://arxiv.org/abs/2009.02987
Autor:
Harashima, Yosuke, Tamai, Keiichi, Doi, Shotaro, Matsumoto, Munehisa, Akai, Hisazumi, Kawashima, Naoki, Ito, Masaaki, Sakuma, Noritsugu, Kato, Akira, Shoji, Tetsuya, Miyake, Takashi
Publikováno v:
Phys. Rev. Materials 5, 013806 (2021)
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
Externí odkaz:
http://arxiv.org/abs/2007.14101
Autor:
Nakano, Takashi, Harashima, Yosuke, Chokawa, Kenta, Shiraishi, Kenji, Oshiyama, Atsushi, Kangawa, Yoshihiro, Usami, Shigeyoshi, Mayama, Norihito, Toda, Kazuya, Tanaka, Atsushi, Honda, Yoshio, Amano, Hiroshi
Publikováno v:
Appl. Phys. Lett. 117, 012105 (2020)
Recent experiments suggest that Mg condensation at threading dislocations induce current leakage, leading to degradation of GaN-based power devices. To study this issue, we perform first-principles total-energy electronic-structure calculations for v
Externí odkaz:
http://arxiv.org/abs/2004.06876
Publikováno v:
Scripta Mater. 179, 12, 2020
The structural stability of CeFe$_{12}$ is investigated by using first-principles calculation. The formation energies of CeFe$_{12}$ relative to the Ce$_{2}$Fe$_{17}$ + bcc-Fe phase and to the CeFe$_{2}$ + bcc-Fe phase are calculated with the assumpt
Externí odkaz:
http://arxiv.org/abs/1908.02926
Publikováno v:
Phys. Rev. Materials 3, 053807 (2019)
We propose a framework for optimization of the chemical composition of multinary compounds with the aid of machine learning. The scheme is based on first-principles calculation using the Korringa-Kohn-Rostoker method and the coherent potential approx
Externí odkaz:
http://arxiv.org/abs/1903.09385