A polymorph of RuI3 synthesized under high pressure was found to have a two-layered honeycomb structure. The resistivity of RuI3 exhibits a semimetallic behavior, in contrast to insulating properties in α-RuCl3. In addition, Pauli paramagnetic behavior was observed in the temperature dependence of a magnetic susceptibility and a nuclear spin-lattice relaxation rate 1/T1. The band structure calculations indicate that contribution of the I 5p components to the low-energy t2g bands effectively decreases Coulomb repulsion, leading to semimetallic properties. The physical properties also suggest strong electron correlations in RuI3.
@article{arxiv.2109.12864,
title = {Strongly electron-correlated semimetal RuI$_3$ with a layered honeycomb structure},
author = {Kazuhiro Nawa and Yoshinori Imai and Youhei Yamaji and Hideyuki Fujihara and Wakana Yamada and Ryotaro Takahashi and Takumi Hiraoka and Masato Hagihala and Shuki Torii and Takuya Aoyama and Takamasa Ohashi and Yasuhiro Shimizu and Hirotada Gotou and Masayuki Itoh and Kenya Ohgushi and Taku J Sato},
journal= {arXiv preprint arXiv:2109.12864},
year = {2021}
}