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The behaviour of isothermal phase transformation, during ageing at 250 °C, in 2Y-TZP and related microstructural development, were investigated. The mode of microstructural development due to isothermal phase transformation was greatly dependent on grain size and the density of the sintered body. Isothermal phase transformation and related microstructural changes began at the specimen surface, near the pores, where the change of strain free energy for a t-m transformation was small and water vapour was easily contacted. The transformed region showed porous microstructures, which appeared due to the formation of cracks upon isothermal transformation.

Magnetoelectric (ME) effects for lanthanum modified solid solutions have been investigated. The value of magnetoelectric polarization coefficient, up is 10 times greater than that of . The results also show that up is due to a linear coupling between polarization and magnetization, and that up is independent of do magnetic bias and ac magnetic field. The ME effect is believed to be significantly enhanced due to breaking of the cycloidal spin state of a long-period spiral spin structure, via randomly distributed charged imperfections.