Effect of radius of rare earth ions of ferroelastic domain switching of zirconia

Pseudo-single crystals of 3 mol% R₂O₃-ZrO₂(R = Yb, Y, Dy, Gd, Eu and Sm) were unidirectionally compressed in the range of 100 to 1000 MPa at 700°C to examine the effect of additive cation on ferroelastic domain switching. The critical stress linearly increased with increasing radius of additive cation. The crystal lattice that solutionized larger additive cation dilated extensively, and was compressed heavily by adjacent lattices. This lattice compression seemed to prevent domain switching. On the other hand, as the critical stress was proportional to the elastic strain energy stored in the crystal lattice, this implies that the activation energy of domain switching increased by the elastic strain energy.