Two-dimensional (2D) chromium-sulfides are synthesized by molecular beam epitaxy using graphene as a substrate. Structure characterization by employing scanning tunneling microscopy and low energy electron diffraction indicates that there are two 2D phases, Cr2S3-2D and Cr232S4-2D, which have not been reported before. Cr232S4-2D is related to bulk Cr5S6, but thinner than a bulk unit cell. For Cr2S3-2D, an even thinner material, no bulk counterpart exists. Both 2D materials are found to be structurally stable under ambient conditions and exhibit interesting electronic properties. Extensive first-principles calculations provide further insight into the electronic structure of these systems and indicate that they should be magnetic. Although single layers of CrS2 were predicted to be stable by density functional theory calculations and reported in previous experimental studies, we were unable to synthesize CrS2 under our range of experimental conditions.
@article{arxiv.2501.09510,
title = {Which chromium-sulfur compounds exist as 2D material?},
author = {Affan Safeer and Mahdi Ghorbani-Asl and Wouter Jolie and Arkady V. Krasheninnikov and Thomas Michely and Jeison Fischer},
journal= {arXiv preprint arXiv:2501.09510},
year = {2025}
}