Thermodynamic stability of thin ferroelectric films

It is shown that the residual depolarization field in a ferroelectric thin film which arises from the incomplete cancellation of polarization and compensation charge in a semiconducting electrode, introduces modifications in the spontaneous polarization and transition temperature. It is also found that below a certain critical thickness the ferroelectric polar state is thermodynamically unstable. For triglycine sulphate the critical thickness is calculated to be 0.4 μm. © 1972.