Probing Ferroelectricity in Thin-film Perovskite SnTiO$_3$ with First-principles Structural Instability Analysis

Perovskite SnTiO$_3$ has been recently identified in a number of computational studies as an attractive, environmentally-friendly material with potential to replace ferroelectric PbTiO$_3$. However, additional computational evidence suggests that bulk perovskite SnTiO$_3$ may be metastable. Using density-functional theory and phonon-band instability analysis, we investigate avenues for epitaxial stabilization of ferroelectric perovskite SnTiO$_3$ thin films with applied strains of up to $\pm$ 2\%.