Temperature-dependent transport properties of a FeTe compound

摘要

Temperature-dependent transport properties of a FeTe parent compound have been investigated by measurements of electrical resistivity p(T), thermal conductivity k(T) and Seebeck coefficient S(T). The sample was synthesized using a standard solid state reaction route via vacuum encapsulation and characterized by X-ray diffraction spectroscopy, which indicated a tetragonal phase with the space group PA/nmm. The resistivity measurement data of the parent FeTe compound do not exhibit superconductivity however, it shows an anomaly in the temperature-dependent resistivity at around 67 K, which corresponds to structural phase transition in the vicinity of a magnetic phase transition. In the low temperature regime, Seebeck coefficient, S(T), exhibited an anomalous dip feature and negative throughout the temperature range, indicating an electron-like, single band charge carrier mechanism. We have also estimated the power factor and thermoelectric figure of merit ZT, which is found to be significantly smaller than other compositions of iron chalcogenides.