125Te synchrotron-radiation-based Mössbauer spectroscopy of Fe1.1Te and FeTe0.5Se0.5

The 125Te Mössbauer spectra of Fe1.1Te and FeTe0.5Se0.5 were measured using synchrotron-radiation-based Mössbauer spectroscopy. The hyperfine field of Te in the antiferromagnetic phase of Fe1.1Te was evaluated to be 4(1) T at 20 K, and this hyperfine field is considered to be due to the transferred hyperfine field from Fe magnetic moments. The evaluated hyperfine field was comparatively large, suggesting the strong correlation with the magnetic moment of Fe that forms a double-stripe type magnetic structure. For the superconductor FeTe0.5Se0.5, no marked change in its Mössbauer parameters was observed below or above the superconducting transition temperature, indicating that the change in the electronic state of Te was small. (author)