The crystal structure, magnetic ordering, and electrical resistivity of TlFe1.6Se2 were studied at high pressures. Below ~7 GPa, TlFe1.6Se2 is an antiferromagnetically ordered semiconductor with a ThCr2Si2-type structure. The insulator-to-metal transformation observed at a pressure of ~ 7 GPa is accompanied by a loss of magnetic ordering and an isostructural phase transition. In the pressure range ~ 7.5 - 11 GPa a remarkable downturn in resistivity, which resembles a superconducting transition, is observed below 15 K. We discuss this feature as the possible onset of superconductivity originating from a phase separation in a small fraction of the sample in the vicinity of the magnetic transition.
@article{arxiv.1708.07702,
title = {Pressure-induced magnetic collapse and metallization of $\mathrm{TlF}{\mathrm{e}}_{1.6}\mathrm{S}{\mathrm{e}}_{2}$},
author = {Pavel G. Naumov and Kai Filsinger and Sergii I. Shylin and Oleg I. Barkalov and Vadim Ksenofontov and Yanpeng Qi and Taras Palasyuk and Walter Schnelle and Sergey A. Medvedev and Martha Greenblatt and Claudia Felser},
journal= {arXiv preprint arXiv:1708.07702},
year = {2017}
}