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 3h 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 165MPa 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 3h 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 16.66K and 7.5K, respectively.