High Curie temperature and strain-induced semiconductor-metal transition with spin reorientation transition in 2D CrPbTe3 monolayer.

One of the major obstacles for Cr-based 2D materials such as CrI3, CrSiTe3 and CrGeTe3 for spintronics applications is their low Curie temperature. Herein, we investigated the strain-induced magnetic properties of 2D CrPbTe3 (CPT) monolayer belonging to members of the Cr-based 2D family. We explored the possibility of the fabrication of 2D layer through the mechanical stability, dynamical stability, formation energy, cohesive energy and thermal stability calculations. We found ferromagnetic ground state and the pristine CrPbTe3 monolayer had an indirect band gap of 0.25 eV with an in-plane magnetic anisotropy of -1.37 meV cell-1. The Curie temperature was 110 K and this is much larger than that of CrI3, CrSiTe3 and CrGeTe3. Under 4% tensile strain, the band gap was increased to 0.45 eV and the Curie temperature was increased to 150 K. We found strain-induced semiconductor-metal transition at 3% compressive strain and also spin reorientation transition from in-plane to perpendicular magnetic anisotropy at 4% compressive strain, and the perpendicular magnetic anisotropy energy was almost three times larger than that of the CrGeTe3 layer. Our finding may suggest that the CrPbTe3 system can be utilized for spintronics and straintronics applications.