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arXiv · 2310.00652

Allotropic transition of Dirac semimetal α-Sn to superconductor β-Sn induced by irradiation of focused ion beam

Kohdai Inagaki·Keita Ishihara·Tomoki Hotta·Yuichi Seki·Takahito Takeda·Tatsuhiro Ishida·Daiki Ootsuki·Ikuto Kawasaki·Shin-ichi Fujimori·Masaaki Tanaka·Le Duc Anh·Masaki Kobayashi
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Abstract

Diamond-type structure allotrope α-Sn is attracting much attention as a topological Dirac semimetal (TDS). In this study, we demonstrate that α-Sn undergoes a phase transition to another allotrope β-Sn with superconductivity at low temperature by irradiating with a focused Ga ion beam (FIB). To clarify the transition mechanism, we performed X-ray photoemission spectroscopy (XPS) measurements on an α-Sn thin film irradiated with FIB and an as-grown α-Sn thin film. The XPS results suggest that the local annealing, which is one of the side effects of FIB, causes the transformation from α-Sn into β-Sn. Furthermore, the difference in the chemical states between α-Sn and β-Sn can be quantitatively explained by the crystal structures rather than the degree of metallicity reflecting the conductivity. These results propose a new way of fabricating TDS/superconductor in-plane heterostructures based on α-Sn and β-Sn.

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Kohdai Inagaki, Keita Ishihara, Tomoki Hotta, Yuichi Seki, Takahito Takeda, Tatsuhiro Ishida, Daiki Ootsuki, Ikuto Kawasaki, Shin-ichi Fujimori, Masaaki Tanaka, Le Duc Anh, Masaki Kobayashi. 2023-10-01. Allotropic transition of Dirac semimetal α-Sn to superconductor β-Sn induced by irradiation of focused ion beam. https://arxiv.org/abs/2310.00652

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