Effects of strain on electronic and magnetic properties of Co/WS$_2$ junction: a density functional and Monte Carlo study

Abstract

In this work, density functional computations and Monte Carlo simulations are performed to investigate structural, electronic, magnetic, and thermodynamic properties of Co/WS$_2$ junction, a semiconductor WS$_2$ monolayer covered by a ferromagnetic cobalt monolayer. In addition to a conventional semilocal exchange-correlation functional, three nonlocal functional, including the novel ACBN0 scheme, are applied to obtain reliable electronic and magnetic properties. It is argued that the ACBN0 scheme, is very efficient for first principles description of the Co/WS$_2$ junction. The obtained electronic structures evidence a trustworthy half-metallic gap in the majority spin channel of the lowest energy configuration of the junction, promising for spintronic applications. The obtained magnetic thermodynamics properties from Monte Carlo simulations predict a Curie temperature of about 110\,K, which is far small for device applications of this junction. The electronic and magnetic properties of the system are calculated under various compressive and tensile strains and it is shown that a tensile strain of about 4\% may effectively improve thermal stability of half-metallic ferromagnetism in the Co/WS$_2$ junction.