@misc{ghazanfari_large_exchange_2022, 
author={Ghazanfari, M. R.,Santhosh, A.,Siemensmeyer, K.,Fuß, F.,Staab, L.,Vrijmoed, J. C.,Peters, B.,Liesegang, M.,Dehnen, S.,Oeckler, O.,Jerabek, P.,Thiele, G.},
title={Large Exchange Bias, High Dielectric Constant, and Outstanding Ionic Conductivity in a Single-Phase Spin Glass},
year={2022},
howpublished = {journal article},
doi = {https://doi.org/10.1002/aelm.202200483},
abstract = {The multigram synthesis of K2[Fe3S4] starting from K2S and FeS is presented, and its electronic and magnetic properties are investigated. The title compound obtains a defect variant of the K[Fe2Se2] structure type. Dielectric and impedance measurements indicate a dielectric constant of 1120 at 1 kHz and an outstanding ionic conductivity of 24.37 mS cm–1 at 295 K, which is in the range of the highest reported value for potential solid-state electrolytes for potassium-ion batteries. The Seebeck coefficient of the n-type conductor amounts to −60 µV K−1 at 973 K. The mismatch of the measured electrical resistivity and the predicted metal-like band structure by periodic quantum chemical calculations indicates Mott insulating behavior. Magnetometry demonstrates temperature-dependent, large exchange bias fields of 35 mT, as a consequence of the coexistence of spin glass and antiferromagnetic orderings due to the iron vacancies in the lattice. In addition, the decreasing training effects of 34% in the exchange bias are identified at temperatures lower than 20 K. These results demonstrate the critical role of iron vacancies in tuning the electronic and magnetic properties and a multifunctional material from abundant and accessible elements.},
note = {Online available at: \url{https://doi.org/10.1002/aelm.202200483} (DOI). Ghazanfari, M.; Santhosh, A.; Siemensmeyer, K.; Fuß, F.; Staab, L.; Vrijmoed, J.; Peters, B.; Liesegang, M.; Dehnen, S.; Oeckler, O.; Jerabek, P.; Thiele, G.: Large Exchange Bias, High Dielectric Constant, and Outstanding Ionic Conductivity in a Single-Phase Spin Glass. Advanced Electronic Materials. 2022. vol. 8, no. 11, 2200483. DOI: 10.1002/aelm.202200483}}