388 / 2019-02-28 16:36:44

Pressure Induced Structure Transition and Superconductivity in Narrow-Gap Seminconductor CsBi4Te6

CBT,high pressure,superconductivity,disorder

全体主题 > High Pressure Physics and Materials Science

CsBi4Te6 (CBT) is a quasi-1D narrow-gap (0.08 eV) semiconductor. It is also one of the best thermoelectric materials. The CBT crystallizes as highly anisotropic needles in the monoclinic space group C2/m. It is also found that CBT shows superconductivity with Bi rich or Cs vacancies.
Here, we report high pressure structure and transport study of CBT up to 45 GPa. We found that CBT undergoes the first structure transition at around 5 GPa with a change of resistance slope. At around 13 GPa, CBT shows superconductivity at around 4 K. The superdoncuctivity appears with the appearance of a new disorder bcc phase. Further compress to 20 GPa, Tc rises to 7.5 K and the structure change to disorder bcc phase completely. Tc keeps at this temperature to 45 GPa, with only a little decrease. Our finding helps to understand the properties of CBT and to explore the superconductivity in disorder system under high pressure.