An investigation of the electronic structure of Cu2FeSn3-xTixS8 (0 %26lt;= x %26lt;= 3) thiospinel spin-crossover materials by X-ray absorption spectroscopy and electronic structure calculations

作者：Hayes John R; Grosvenor Andrew P^*

来源：Journal of Solid State Chemistry, 2013, 197: 532-542.

DOI：10.1016/j.jssc.2012.08.057

• Spin-crossover transition
• XANES
• Electronic structure calculations
• Thiospinels

The spin-crossover (SCO) transition is an interesting phenomenon in which a metal center transitions from a low-spin state to a high-spin state (or vice versa) upon some external perturbation. Only a few studies have investigated the SCO transition in crystalline compounds and the Cu2FeSn3-xTixS8 thiospinels present an opportunity for such a study. Fe K-XANES has been used to investigate the changes in the electronic structure of these materials as Ti is substituted for Sn. The room-temperature Fe K-edge XANES spectra showed that the pre-edge intensity increased with increasing Ti content as a result of the Fe-S bond becoming more covalent. Ti K- and S K-edge XANES spectra confirmed this analysis. Electronic structure calculations were also performed to aid in the interpretation of the XANES spectra. Temperature-dependent Fe K-edge XANES spectra were further collected to study the SCO transition and showed that the main-edge features decreased in intensity with decreasing temperature, corresponding to variations in the average Fe2+ spin-state.

• 出版日期2013-1