Pyrochlore/perovskite phase transformation in lead zinc-niobate based ceramics

A phase transformation from pyrochlore to perovskite takes place during the firing of Pb(Zn_1/3Nb_2/3)O₃ (PZN)-based ceramics. Stabilization of the perovskite phase in PZN-based ceramics is closely related to the type of additive and its amount. A thermodynamic model based on the chemical potential of the system that accounts for the stabilization of the perovskite phase in terms of the internal stress introduced by the additives is proposed. The additives that stabilize the perovskite phase in PZN-based ceramics are those materials that can initiate the formation of perovskite subgrains