Ghazanfari Mohammad R, Siemensmeyer Konrad, Santhosh Archa, Vrijmoed Johannes C, Tallu Mirko, Dehnen Stefanie, Jerabek Paul, Thiele Günther
Fachbereich Biologie, Chemie, Pharmazie, Freie Universität Berlin, Fabeckstr. 34-36, Berlin 14195, Germany.
Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, Berlin 14109, Germany.
Inorg Chem. 2023 Sep 25;62(38):15358-15366. doi: 10.1021/acs.inorgchem.3c00008. Epub 2023 Sep 13.
We introduce Na[FeS], 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 Na[FeS] as a sustainable multifunctional material with potential for a variety of electronic and magnetic applications.
