We report the synthesis of a new quasi one-dimensional (1D) iron selenide. Ba9Fe3Se15 was synthesized at high temperature and high pressure of 5.5 GPa and systematically studied via structural, magnetic and transport measurements at ambient and at high-pressures. Ba9Fe3Se15 crystallizes in a monoclinic structure and consists of face-sharing FeSe6 octahedral chains along the c axis. At ambient pressure it exhibits an insulating behavior with a band gap ~460 meV and undergoes a ferrimagnet-like phase transition at 14 K. Under high pressure, a complete metallization occurs at ~29 GPa, which is accompanied by a spin state crossover from high spin (HS) state to low spin (LS) state. The LS appears for pressures P >36 GPa.
@article{arxiv.2102.03708,
title = {Crystal structure and properties of iron-based spin-chain compound Ba9Fe3Se15},
author = {Jun Zhang and Alexander C. Komarek and Meiling Jin and Xiancheng Wang and Yating Jia and Jianfa Zhao and Wenmin Li and Zhiwei Hu and Wei Peng and L. H. Tjeng and Zheng Deng and Runze Yu and Shaomin Feng and Sijia Zhang and Min Liu and Yi-feng Yang and Hong-ji Lin and Chien-Te Chen and Xiaodong Li and Jinlong Zhu and Changqing Jin},
journal= {arXiv preprint arXiv:2102.03708},
year = {2021}
}