@article{71658ff617134f70a8e732f76ac3f246,
title = "Enhancement of spin current generation in epitaxial α-Ta/CoFeB bilayer",
abstract = "We report the enhancement of the spin Hall effect in a (111)-oriented epitaxial α-Ta/CoFeB bilayer system, which was previously believed to show the small spin Hall angle (SHA). The SHA of the epitaxial α-Ta/CoFeB structure estimated by spin Hall magnetoresistance measurement is 0.15, a value that is 1.5 times larger than the conventional amorphous-Ta/CoFeB structure. Effective SHA estimated by harmonic Hall measurement qualitatively supports the SMR result, whereas the strength of the field-like field of epitaxial α-Ta samples is similar to that of amorphous Ta samples. According to the resistivity dependence on the SHA, the origin of the enhanced SHA in epitaxial α-Ta is due to the extrinsic contribution to the SHA.",
author = "Hiromu Gamou and Ye Du and Makoto Kohda and Junsaku Nitta",
note = "Funding Information: The authors acknowledge financial support from the Japanese Ministry of Education, Culture, Sports, Science, and Technology (MEXT) in Grant-in-Aid for Scientific Research (Grants No. 15H05699, No. 15H02099, No. 15H05854, and No. 25220604) and the EPSRC-JSPS Core-to-Core program. H.G. acknowledges support from the Grant-in-Aid for JSPS Research Fellow (No. 18J11981) and the Graduate Program in Spintronics at Tohoku University. The authors also thank T. Ikeda, T. Mitate, and M. Morita for taking and analyzing the TEM images. The authors are grateful to C. O. Avci, K. Nakamura, and S. Karube for valuable discussions. Publisher Copyright: {\textcopyright} 2019 American Physical Society.",
year = "2019",
month = may,
day = "9",
doi = "10.1103/PhysRevB.99.184408",
language = "English",
volume = "99",
journal = "Physical Review B",
issn = "2469-9950",
publisher = "American Physical Society",
number = "18",
}