Phenomenological description of coercive field decrease in ferroelectric semiconductors with charged inhomogeneities

We have proposed the phenomenological description of polarization switching peculiarities in ferroelectric semiconductors with charged defects and prevailing extrinsic conductivity. We have exactly modified the Landau-Ginzburg approach and shown that the macroscopic state of the aforementioned inhomogeneous system can be described by three coupled equations for three order parameters. The coercive field values well below the thermodynamic one have been obtained in the framework of our model. This result agrees much better with experiments for bulk samples than predictions of the classical Landau-Ginzburg theory.