The comprehensive phase evolution for Bi2Te3 topological compound as function of pressure

The recently discovered three-dimensional topological insulator Bi2Te3 is studied as function of pressure in terms of crystal structures, resistance, and Hall coefficient. The superconductivity is found in phase I (ambient phase) Bi2Te3 with T-c similar to 3 K, which is related to the topological features. The evolution of crystal structure with pressure is investigated by high pressure synchrotron radiation experiments that reveal structural transitions occurring at about 8 GPa, 13 GPa, and 16 GPa, respectively. Furthermore, the high pressure phases of Bi2Te3 are also superconducting but with much higher T-c similar to 8 K. The superconducting transitions are compared with those for Bi, Te elements. A global phase diagram of Bi2Te3 as function of pressure up to 30 GPa is obtained. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4726258]