| مستخلص: |
The full-potential linearized augmented plane wave plus local orbital method is utilized for exploring the electronic, magnetic, and magneto-optical properties of the NiX2 (X=Cl, Br, and I) single layer. The first-principles calculation demonstrates that these compounds are ferromagnetic indirect semiconductors, and the energy band gaps of NiX2 for X=Cl, Br, and I are 3.888, 3.134, and 2.157 eV, respectively. The magnetic moments of Ni atoms in NiX2 monolayer are 1.656, 1.588, 1.449 µB, and their magneto-crystalline anisotropy energies are 0.167, 0.029, 0.090 meV, respectively. Based on the macro-linear response theory, we systematically studied the influences of the external magnetic field and out-of-plane strain on the magneto-optical Kerr effect (MOKE) spectrum of the NiX2 single layer. It is found that, when the external magnetic field is perpendicular to the sample plane, the value of the Kerr rotation angle reaches the maximum, and the single-layer NiI2 material has a Kerr rotation angle of 1.89° at the photon energy of 1.986 eV. Besides, the Kerr rotation spectrum of NiCl2 and NiBr2 monolayers redshift as the out-of-plane strain increases, while NiI2 monolayer blueshifts. Accurate computation of the MOKE spectrum of NiX2 materials provides an opportunity for applications of 2D magnetic material ranging from sensing to data storing. [ABSTRACT FROM AUTHOR] |