Existence conditions for ferroaxial materials

All 212 species of structural phase transitions with a macroscopic symmetry breaking were inspected with respect to the simultaneous occurrence of the ferroelastic, ferroelectric, and ferroaxial properties.

For each species, a matrix of representative equilibrium property tensors in both high-symmetry and low-symmetry phases, showing emergence of spontaneous components, were explicitly worked out [http://palata.fzu.cz/species/13x13axial]. Results can serve as a useful tool in search of fundamentally new material properties [J. Hlinka et al., Phys. Rev. Lett. 116, 177602 (2016)].

Figure: Dichromatic matrix of material property tensors for a symmetry-breaking structural phase transition from tetragonal to monoclinic phases, showing relations between tensor components of both phases and emergence of spontaneous components (red points).