Temperature dependence of emerging properties of ferroelastic domain walls in CaTiO3

Molecular dynamics simulations of the well-known ferroelastic material, CaTiO3, reproduce the experimentally observed bulk and wall properties. We show that Landau–Ginzburg potentials are an excellent approach to estimate bulk properties like the phase diagram and the ferroelastic bulk deformation. Most importantly, the known ferroelastic wall properties are reproduced and predicted, when unknown. The main emerging property is the wall polarization Pwall, which is as large as some of the best ferroelectric bulk materials. The temperature dependence of Pwall shows a near-linear decay from room temperature to the transition point. We argue that the most promising experimental technique to test our results is the measurement of the second harmonic generation of domain walls over large temperature intervals.