Hubbard U library and high throughput exploration of spin Hamiltonian parameters for the rational design of metal trihalides MX$_3$ (M={Ti,V,Cr,Fe}, X={Cl,Br,I}) with high Curie temperature

Abstract

Metal trihalides (MX$_3$) are the most important family of 2D magnetic materials, being the chromium trihalides the most studied 2D magnets. The discovery of CrI$_3$, the recent obtention of CrCl$_3$ in-plane magnetic monolayer and the role of CrBr$_3$ inducing topological superconductivity in NbSe$_2$, may serve to showcase the active research being done in this family nowadays. Despite the high impact of these materials, most of the members in the MX$_3$ family are still unexplored and constitute an untapped source of interesting physical properties. Stimulated by the most recent advances in straintronics and aware of the crucial role of the dielectric screening, we present here a high throughput methodology to automatize the exploration of 2D materials. Employing this methodology, we studied the MX$_3$ family (M= Cr, Fe, V, Ti; X= Cl, Br, I) with the goal of advancing towards the solution of the most problematic issue in these materials, namely the Curie temperature. We use a particular case to show how this methodology allows us to obtain a complete description of the magnetic interaction picture (J$_{iso}$, J$_{xx}$, J$_{yy}$, J$_{zz}$) up to third neighbors condensed in a single effective equation per parameter, describing magnetic interaction in terms of the strain and the Hubbard U parameter. Additionally, and because of the important role of the Hubbard U in MX$_3$ materials, we provide a library of self-consistent calculated Hubbard U for the principal pseudopotential families. The work presented herein advances in the description of the still unexplored MX$_3$ materials, opening the door to a rational design of 2D magnetic materials