Layer dependent magneto-optical properties of ferromagnetic chromium triiodide: An ab initio study

Two-dimensional materials (TDM) have attracted enormous attention because of their fascinating properties for next-generation device applications. TDM of graphene and beyond-graphene materials such as transition metal dichalcogenides, are receiving increasing interests because of their excellent applications on electronic and optoelectronics. Ferromagnetism and half-metallicity have been predicted recently in TDM, which promise exciting potentials for semiconductor spintronics. This unveils the importance of the magnetism and magneto-optical (MO) properties of TDM for a better understanding of magnetism in these materials. In the present work, we perform a systematic ab initio density functional study on the MO Kerr and Faraday effects of bulk and monolayer (ML) ferromagnetic (FM) CrI₃. We report the electronic structure and optical conductivity of semiconductor CrI₃ for both bulk and ML. Furthermore, we also study the MO properties of the FM CrI₃, and find that for bulk and ML MO Kerr and Faraday effects to be high compared to the traditional MO materials. Thin film ML of CrI₃ with SiO₂ as a substrate, the MO Kerr rotation is found to be in good agreement with the recent experimental work, which shows that FM CrI₃ is an excellent family of TDM for MO and spintronic nanodevices.