Interplay of electronic and magnetic phase modulation in a spin-polarised nanomagnet

The 2H-phase of monolayer vanadium diselenide (VSe) has recently emerged as a very intriguing material in spintronics due to its intrinsic ferromagnetism with semiconducting properties. In the present work, first-principles based calculations have been employed to systematically study the electronic, magnetic, and optical behaviour of 2D VSe for investigating the impact of different external excitations such as strain, electric field, and pressure on the material. Specifically, the magnetic moment, band gap, Curie temperature (T), and absorption coefficient could be modulated, as the states near the Fermi level are mainly contributed by the in-plane atomic orbitals. The presence of different electronic phases in 2D VSe can be modulated from semiconductor to half-metal and even normal metal under the influence of external stimuli. Furthermore, the in-plane biaxial strain can effectively tune the T and attains a maximum value of 354K at = 6%. The maximum observed absorption coefficient is found to be 5.05 10 cm (at 1.4 eV) under the applied pressure of 30 GPa, indicating that the VSe exhibits strong light absorption in the visible region. The unique combination of electronic phases, robust ferromagnetism, and optical activity makes the 2H-VSe a suitable candidate for flexible electronic, optoelectronic, and spintronic applications.