Insights in the A- and B-site's Radii Influence in the Polar Character of ABF4

Here, we present the study of the ferroelectricity in the ABF4 materials with A = (Sr, Ba) and B = (Mg, Zn). This theoretical study was performed based-on first-principles calculations within the density-functional theory, DFT, formalism. We found that the geometric ferroelectricity in ABF4 layered compounds can be tuned by changing the A-site with Sr and Ba cations and B-sites with Mg and Zn atoms. Additionally, we studied the stability of the phases as a function of the A and B cations' occupation preference. We observed a layer-by-layer disposition, as a ground state, when the A-site has different compositions of Sr/Ba.