Amine intercalation inFePS3: AFe57Mössbauer study

The methylamine and ethylamine intercalates of ${\mathrm{FePS}}_3$ were prepared, characterized by x-ray diffraction (XRD) and investigated by ${}_{}{}^{57}{}_{}{}^{}\mathrm{Fe}$ Mössbauer spectroscopy. The XRD results show that the intercalate remains monoclinic but exhibits a fairly large expansion of its c axis. The original Mössbauer line of the host ${\mathrm{FePS}}_3$ is absent in all the compounds. The Mössbauer spectra consist of lines originating from modified host lattice and two types of reduced sites created due to transfer of electrons during intercalation. The origin of the observation of two kinds of reduced sites has been suggested. Mössbauer results highlight that beyond a certain concentration of guest species the transferred electrons in the amine intercalates are primarily of delocalized character whereas it is of localized nature in the case of Li intercalated ${\mathrm{FePS}}_3$.