Effect of Te Doping on FeSe Superconductor Synthesized by Powder-In-Tube

FeSe is a superconducting material which has the simplest crystal structure among the Fe-based superconductors. And also, it has no arsenic element that very harmful to the human body. In this study, we analyzed the effects of milling time and Te doping on FeSe superconductors. The synthesis of samples carried out by powder-in-tube method using SS304 stainless steel tube. After the pressing process followed by the sintering process at temperature of 500⁰C for 20 hours, the samples were removed from the tubes. Later, we analyzed its crystal structures, surfaces morphology and the superconductivity properties. δ-FeSe phase (hexagonal, non-superconductor) and β-FeSe (tetragonal, superconductor) were formed in the samples, including minor phases of Fe and Fe3Se4. Te doping made crystal structure changing from β-FeSe and δ-FeSe into FeSe0.5Te0.5, and made onset critical temperature (TC, onset) shifting to higher temperature. Seminar Internasional ISFAP 2016