Spin Glass State in Iron-Doped Bi<sub>2</sub>Fe<sub>0.128</sub>Te<sub>2.844</sub>Se<sub>0.145</sub> Topological Insulator

Abstract

The researching of dependence of magnetization from temperature T and magnetic field in the Bi2Fe0.128Te2.844Se0.145 single-crystal showed that it have spinglass-like state with freezing temperature Tf= 40 K. Its electric resistance up to 100 K is ~ 103 Ohm and decreases with the temperature increase. At T > 110 K electric resistance ~ 10-2 Ohm and magnetization is four times smaller than in spinglass-like state. It can be assumed from these results that this sample is topological insulator at T > 110 K and at small temperature, where it is spinglass-like, offers the breaking of the time reversal symmetry.