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arXiv · 2001.02895

Hybridization between the ligand $p$ band and Fe-3$d$ orbitals in the p-type ferromagnetic semiconductor (Ga,Fe)Sb

Takahito Takeda·Masahiro Suzuki·Le Duc Anh·Nguyen Thanh Tu·Thorsten Schmitt·Satoshi Yoshida·Masato Sakano·Kyoko Ishizaka·Yukiharu Takeda·Shin-ichi Fijimori·Munetoshi Seki·Hitoshi Tabata·Atsushi Fujimori·Vladimir N. Strocov·Masaaki Tanaka·Masaki Kobayashi
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Abstract

(Ga,Fe)Sb is a promising ferromagnetic semiconductor for practical spintronic device applications because its Curie temperature ($T_{\rm C}$) is above room temperature. However, the origin of ferromagnetism with high $T_{\rm C}$ remains to be elucidated. Here, we use soft x-ray angle-resolved photoemission spectroscopy (SX-ARPES) to investigate the valence-band (VB) structure of (Ga$_{0.95}$,Fe$_{0.05}$)Sb including the Fe-3$d$ impurity band (IB), to unveil the mechanism of ferromagnetism in (Ga,Fe)Sb. We find that the VB dispersion in (Ga$_{0.95}$,Fe$_{0.05}$)Sb observed by SX-ARPES is similar to that of GaSb, indicating that the doped Fe atoms hardly affect the band dispersion. The Fe-3$d$ resonant ARPES spectra demonstrate that the Fe-3$d$ IB crosses the Fermi level ($E_{\rm F}$) and hybridizes with the VB of GaSb. These observations indicate that the VB structure of (Ga$_{0.95}$,Fe$_{0.05}$)Sb is consistent with that of the IB model which is based on double-exchange interaction between the localized 3$d$ electrons of the magnetic impurities. The results indicate that the ferromagnetism in (Ga,Fe)Sb is formed by the hybridization of the Fe-3$d$ IB with the ligand $p$ band of GaSb.

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Takahito Takeda, Masahiro Suzuki, Le Duc Anh, Nguyen Thanh Tu, Thorsten Schmitt, Satoshi Yoshida, Masato Sakano, Kyoko Ishizaka, Yukiharu Takeda, Shin-ichi Fijimori, Munetoshi Seki, Hitoshi Tabata, Atsushi Fujimori, Vladimir N. Strocov, Masaaki Tanaka, Masaki Kobayashi. 2020-01-09. Hybridization between the ligand $p$ band and Fe-3$d$ orbitals in the p-type ferromagnetic semiconductor (Ga,Fe)Sb. https://doi.org/10.1103/physrevb.101.155142

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