Teguh Budi Prayitno, Esmar Budi, Riri Jonuarti, Abdul Rahman Mohmad
Investigation of magnetic transition and thermoelectric characteristics in the single-layer metal dibromides 1T-MBr2 (M: Fe and Co) has been performed by generalized Bloch theorem within density functional theory. Using the lowest total energy, we identified the ferromagnetic, spiral, or antiferromagnetic state formed by a flat spiral configuration in the primitive unit cell. For the non-doped case, FeBr2 and CoBr2 possessed the ferromagnetic and spiral ground states, respectively. As the lattice parameter increased, the initial ground state changed to a new ground state, thus creating a magnetic transition. Also, incorporating hole-electron doping led to a magnetic transition, which was sensitive to some lattice parameters. For the optimized lattice parameters, we investigated thermoelectric performance using the initial ground state for some temperatures within the Boltzmann transport theory. We found a low (high) figure of merit in FeBr2 (CoBr2) at the Fermi level only for the paramagnetic state, where the temperature was above the Curie temperature. The emergence of a spiral state and a high figure of merit might lead to multiferroic and thermoelectric materials. © 2025 Elsevier B.V.
Physics Department, Faculty of Mathematics and Natural Science, Universitas Negeri Jakarta, Kampus A Jl. Rawamangun Muka, Jakarta Timur, 13220, Indonesia; Department of Physics, Faculty of Mathematics and Natural Science, Universitas Negeri Padang, Jl. Prof. Dr. Hamka Air Tawar Barat, Padang, 25171, Indonesia; Institute of Microengineering and Nanoelectronics (IMEN) Universiti Kebangsaan Malaysia 43600 UKM Bangi, Selangor, Malaysia
