Possible Topological Phase Transition in Fe-Vacancy-Ordered $\beta$-Fe${}_{4+\delta }$Se${}_5$ Nanowires

Keng-Yu Yeh, Tung-Sheng Lo, Chung-Chieh Chang +4

We studied the electrical transport on $\beta$-Fe${}_{4+\delta }$Se${}_5$ single-crystal nanowires, exhibiting $\sqrt{5}\times \sqrt{5}$ Fe-vacancy order and mixed valence of Fe. We observed a…