Effect of the synthesis conditions on the properties of polycrystalline films of lead zirconate titanate of nonstoichiometric composition

Resumo

The model representations of the formation of the internal fields at the grain boundaries in polycrystalline lead zirconate titanate (PZT) films are discussed. According to the model proposed, the local distortion of the stoichiometric composition of the PZT films caused by the segregation of the oxygen and lead ions from the bulk PZT grains towards their boundaries during high-temperature annealing gives rise to electrical double layers near the grain boundaries and fixes the polarization in these areas. As a result, the ferroelectric polarization that can be switched by the electric field in polycrystalline PZT films decreases.