ScholarWorks@숙명여자대학교

초록

In this study, we performed the first-principles electronic structure calculations within the density functional theory for the twodimensional monolayer of 1T CrSe2 based compounds to show that a substitution of Cr with heavier transition metals induces the stabilization of ferromagnetic phase and it’s closely related to the lattice constant increase. The structural optimization and total energy comparison of the paramagnetic, ferromagnetic (FM), and antiferromagnetic (AFM) phases of the pristine CrSe2 single layer reveals that (1) the in-plane stripe AFM is the ground state while the energy difference between AFM and FM phases is relatively small (~0.03 eV/unit cell) and (ii) an in-plane strain inducing the increase of lattice constant by 2.7% can result in a magnetic phase transition stabilizing the FM state. In fact, we introduce a lattice increase by substituting 50% of 3d Cr with 4d and 5d transition metals, Zr and W, to make Cr0.5Zr0.5Se2 and Cr0.5W0.5Se2 and show that the FM magnetic phase is stabilized. Our calculation indicates that the substitutional doping by Zr results in the in-plane lattice constant increased by 6.8%, being more efficient in using the in-plain strain effect not only to stabilize the ferromagnetic phase but also to increase spin magnetic moment of Cr atom which plays critical role in determination of the magnetic property of the present material.

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