Single-domain perpendicular magnetization induced by the coherent O 2p-Ru 4d hybridized state in an ultra-high-quality SrRuO3 film

Yuki K. Wakabayashi; Masaki Kobayashi; Yukiharu Takeda; Kosuke Takiguchi; Hiroshi Irie; Shin-ichi Fujimori; Takahito Takeda; Ryo Okano; Yoshiharu Krockenberger; Yoshitaka Taniyasu; Hideki Yamamoto

arXiv · 2108.04980

Single-domain perpendicular magnetization induced by the coherent O 2p-Ru 4d hybridized state in an ultra-high-quality SrRuO3 film

Yuki K. Wakabayashi·Masaki Kobayashi·Yukiharu Takeda·Kosuke Takiguchi·Hiroshi Irie·Shin-ichi Fujimori·Takahito Takeda·Ryo Okano·Yoshiharu Krockenberger·Yoshitaka Taniyasu·Hideki Yamamoto

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Abstract

We investigated the Ru 4d and O 2p electronic structure and magnetic properties of an ultra-high-quality SrRuO3 film on SrTiO3 grown by machine-learning-assisted molecular beam epitaxy. The high itinerancy and long quantum lifetimes of the quasiparticles in the Ru 4d t2g-O 2p hybridized valence band are confirmed by observing the prominent well-screened peak in the Ru 3d core-level photoemission spectrum, the coherent peak near the Fermi energy in the valence band spectrum, and quantum oscillations in the resistivity. The element-specific magnetic properties and the hybridization between the Ru 4d and O 2p orbitals were characterized by Ru M2,3-edge and O K-edge soft X-ray absorption spectroscopy and X-ray magnetic circular dichroism measurements. The ultra-high-quality SrRuO3 film with the residual resistivity ratio of 86 shows the large orbital magnetic moment of oxygen ions induced by the strong orbital hybridization of the O 2p states with the spin-polarized Ru 4d t2g states. The film also shows single-domain perpendicular magnetization with an almost ideal remanent magnetization ratio of 0.97. These results provide detailed insights into the relevance between orbital hybridization and the perpendicular magnetic anisotropy in SrRuO3/SrTiO3 systems.

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Yuki K. Wakabayashi, Masaki Kobayashi, Yukiharu Takeda, Kosuke Takiguchi, Hiroshi Irie, Shin-ichi Fujimori, Takahito Takeda, Ryo Okano, Yoshiharu Krockenberger, Yoshitaka Taniyasu, Hideki Yamamoto. 2021-08-11. Single-domain perpendicular magnetization induced by the coherent O 2p-Ru 4d hybridized state in an ultra-high-quality SrRuO3 film. https://arxiv.org/abs/2108.04980

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