Electron Layer and Interface Coupling Cooperatively Induced Magnetic Phase Transition in CrSe ₂ /Electride Ca ₂ N Van Der Waals Heterostructures

The electride, a novel crystalline material that restricts “excess anionic electrons” within subnanometer-sized lattice cages, has emerged as a subject of interest in crystal research. Represented by the Ca2N, this material has garnered attention due to its highly mobile two-dimensional electron gas, offering potential for designing weakly scattering transport channels. In this study, a new magnetic system is developed by forming a CrSe2/Ca2N van der Waals heterostructure based on density functional theory calculations. When combined with the electride Ca2N, a transition from antiferromagnetic to ferromagnetic ground state is observed in CrSe2. In this system, the metallic Ca atoms form exposed electron layers in the electride, revealing the coupling effects arising from the competition between significant charge transfer, direct exchange, and superexchange interactions at the heterostructure interface as two contributing factors to the magnetic phase transition. Furthermore, the enhancement of the in-plane magnetic anisotropy in the CrSe2 monolayer upon forming a heterostructure with Ca2N is attributed to the energy difference between occupied and unoccupied orbitals near the Fermi level. These findings not only provide an effective strategy for manipulating the ground state of magnetic materials on electride substrates, but also pave the way for the construction of multifunctional spintronic devices.