Structural and magnetic properties of Te doped FeSe ?11? type superconductors

This study carried for investigation of Te Doping effect to the Structural and Magnetic Properties of FeSe ?11? Type Iron Based Superconductors .In this study, to determine structure of the samples structural analysis of the samples prepared with FeSe1-xTex initial formula from x= 0.0 to x=1.0 with 0.1 doping ratio steps X-ray diffraction method is used. For the magnetic properties, VSM Magnetometer is used to measure M-H and M-T graphs of bulk samples. Resistivity measurements are investigated with four point method.From the X-ray Diffraction Analysis, main phase and impurity phases of the samples are defined. The critical temperature values (Tc) are observed from M-T graphs and resistivity graphs. From M-H diagrams maximum magnetization and ?M determined.According to the obtained results, FeSe0.5Te0.5 sample showed highest superconducting transition Tc with 13.77 K and 15.7 K from respectively M-T and resistivity measurements. As homogenity most homogenous sample from M-T graph is FeSe0.8Te0.2 sample. According to the magnetization value FeSe0.5Te0.5 has the highest magnetization value.An enhancement of the superconducting transition temperature Tc was observed with the substitution of Te for Se; the Tc has highest value with Te substitution with x=0.5. Above x=0.5 doping ratio superconducting properties decreased and in FeTe sample superconductivity disappeared.