Effects of Substituting Se with Te in the FeSe Compound: Structural, Magnetization and Mössbauer Studies

Polycrystalline samples of FeSe1−x Te x (x=0.00, 0.25, 0.50, 0.75 and 1.00) were synthesized by solid-state reaction to study the effects of substituting Se with Te in the system. The magnetization properties of the resulting compounds were investigated and the crystallographic structures of the samples analyzed through X-ray diffraction. Mossbauer spectroscopy was used to determine the ionic state of the Fe ions and the hyperfine fields. The magnetic susceptibility curves of the samples with x=0.25, 0.50 and 0.75 show superconducting behavior. The lattice parameters and the cell volume increase monotonically with increasing Te concentration and the Mossbauer spectra reveal the absence of internal magnetic hyperfine fields.