Ferroelasticity of t’-ZrO 2

Different materials show ferroelastic behaviour when two conditions are satisfied. Firstly, a diffusionless phase transition from a high-symmetry modification must occur, which generates the ferroelastic material. The phase transformation must lower the point-group symmetry and must generate a lattice distortion. Usually, the ferroelastic material is composed of at least two different variants (domains) with different orientations. The domains are separated by domain walls. Secondly, it must be possible to reorientate the domains by external stresses. The latter poperty is equivalent to «switching» the domains by the migration of domain walls. One modification of zirconia, t'-ZrO 2 , exhibits the ferroelastic behaviour