Electronic properties across the first-order phase transition in Fe 1.11 Te

Abstract

We present electrical resistivity as well as scanning tunneling microscopy and spectroscopy (STM/S) studies on Fe1.11 Te single crystals. For this composition, a first-order phase transition is observed around 57 K This transition is associated with a structural change from the tetragonal P4/nmm to the monoclinic P21/m space group. Also at this temperature, the compound becomes antiferromagnetic (TN = 57 K) and the temperature dependence of the resistivity changes from log(-T) to T2. This observation suggests that the material becomes a Fermi-liquid metal at low temperatures. Metallic behavior is also confirmed in the I - V characteristics of the scanning tunneling spectroscopy measurements taken at T < T N on an atomically resolved surface. © Published under licence by IOP Publishing Ltd.