Critical behavior of the ferromagnets CrI3, CrBr3, and CrGeTe3 and the antiferromagnet FeCl2: A detailed first-principles study
Abstract
We calculate the Curie temperature of layered ferromagnets, chromium tri-iodide (CrI3), chromium tri-bromide (Cr Br3 ), chromium germanium tri-telluride (Cr Ge Te3 ), and the Néel temperature of a layered antiferromagnet iron di-chloride (Fe Cl2 ), using first-principles density functional theory calculations and Monte Carlo simulations. We develop a computational method to model the magnetic interactions in layered magnetic materials and calculate their critical temperature. We provide a unified method to obtain the magnetic exchange parameters (J ) for an effective Heisenberg Hamiltonian from first principles, taking into account both the magnetic ansiotropy as well as the out-of-plane interactions. We obtain the magnetic phase change behavior, in particular the critical temperature, from the susceptibility and the specific-heat, calculated using the three-dimensional Monte Carlo (METROPOLIS) algorithm. The calculated Curie temperatures for ferromagnetic materials (CrI3, Cr Br3 , and Cr Ge Te3 ), match well with experimental values. We show that the interlayer interaction in bulk Cr I3 with R 3 ¯ stacking is significantly stronger than the C 2 /m stacking, in line with experimental observations. We show that the strong interlayer interaction in R 3 ¯ Cr I3 results in a competition between the in-plane and the out-of-plane magnetic easy axes. Finally, we calculate the Néel temperature of Fe Cl2 to be 47 ±8 K and show that the magnetic phase transition in Fe Cl2 occurs in two steps with a high-temperature intralayer ferromagnetic phase transition and a low-temperature interlayer antiferromagnetic phase transition.
- Publication:
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Physical Review B
- Pub Date:
- January 2021
- DOI:
- 10.1103/PhysRevB.103.014432
- arXiv:
- arXiv:2007.14379
- Bibcode:
- 2021PhRvB.103a4432T
- Keywords:
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- Condensed Matter - Mesoscale and Nanoscale Physics;
- Condensed Matter - Materials Science
- E-Print:
- Phys. Rev. B 103, 014432 (2021)