Strong effect of compressive strain on Ni-doped monolayer WSe2

Highlights: • Ni doping induces magnetism in the WSe₂ monolayer. • The doped system shows half-metal feature from −2% to −7% strain. • The largest half-metallic gap is 89 meV at −5% tensile strain. • The biggest magnetic moment is 3.280 μ_Bat-3% compressive strain. We study the effect of strain on electronic and magnetic properties of Ni-doped monolayer WSe₂ by using a method of plane wave potential technique based on the density function theory. We find that Ni-doped monolayer WSe₂ becomes a magnetic metal material, and the magnetic moment is 1.466 μ_B. When we apply different compressive strain, Ni-doped WSe₂ shows half-metallic from magnetic properties firstly. With increasing compressive strain, Ni-doped WSe₂ shows magnetic metal properties from −8% to −10%. The magnetic moment also increases firstly and then decreases with increasing compressive strains, the biggest magnetic moment is 3.280 μ_B at −3% compressive strain and the minimum magnetic moment is 0.658μ_B at −10% compressive strain. While, the magnetic moment increases slowly with increasing tensile strain and comes to 1.812μ_B at 10% tensile strain. By comparison, we find that there is stronger effect of compressive strain on electronic and magnetic properties of this doped system than that of tensile strain.