Preparation of FeSeTe superconductor by conventional method

Abstract

We have synthesized the FeSe and FeSe0.5Te0.5 superconductors by using a conventional solid-state reaction. The starting materials which consisted of iron, selenium, and tellurium powder were weighed in the stoichiometry ratio Fe:Se = 1:1 and Fe:Se:Te = 1:0.5:0.5. The starting materials were ground using an agate mortar for 3 h in the air. The milled powders were separated into 2 variations respectively the vacuum and powder in a sealed tube (PIST) method. For the vacuum method, the milled powders were weighed and compacted with a pressure of 165 MPa using a hydraulic press machine to form a pellet shape. For another method, the milled powders were inserted into the stainless-steel (SS316) tube and then compacted. Finally, the pellet and compacted tube were then sintered at the temperature of 745°C and 845°C for 3 h and left in the furnace to room temperature. Based on the resistivity measurement, the best sample was obtained in the FeSe0.5Te0.5 sample that sintered at the temperature of 745°C using the vacuum method. The critical temperature onset (Tconset) and critical temperature zero (Tczero) of the best sample were found at 16.66 K and 7.5 K, respectively.