Ghazanfari, M.R.; Siemensmeyer, K.; Santhosh, A.; Vrijmoed, J.C.; Tallu, M.; Dehnen, S.; Jerabek, P.; Thiele, G.: Low-Cost, Multifunctional, and Sustainable Sodium Sulfido Ferrate(II). Inorganic Chemistry 62 (2023), p. 15358-15366
10.1021/acs.inorgchem.3c00008
Abstract:
We introduce Na2[Fe3S4], comprising anionic layers, synthesized by a simple and straightforward solid-state method based on the fusion of binary sulfides of abundant sodium and iron. The structure crystallizes in a trigonal lattice with honeycomb cavities, as well as 25% of statistical iron vacancies in the crystal structure. The compound depicts high dielectric constants from 998 to 1850 at a frequency of 1 kHz depending on the sintering temperature, comparable with benchmark dielectric materials. According to the complex electrochemical impedance results, the compound depicts an electrical conductivity at ambient temperature. Optical investigations reveal a band gap of 1.64 eV, which is in agreement with an electronic band gap of 1.63 eV computed by density functional theory calculations. Magnetometry results reveal an antiferromagnetic behavior with a transition at 120 K. These findings introduce Na2[Fe3S4] as a sustainable multifunctional material with potential for a variety of electronic and magnetic applications.