Effect of asymmetrical interface charges on the hysteresis and domain configurations of ferroelectric thin films

Official URL: http://dx.doi.org/10.1080/10584587.2011.575017

We simulate the hystereses and domain properties of ferroelectric films with space charges in thick (similar to 200 nm) and thin structures (similar to 20 nm). Epitaxial (001) PbZr(0.3)Ti(0.7)O(3) thin films sandwiched between metallic electrodes on (001) SrTiO(3) substrates are taken as a model system. We show that space charge accumulated near the metal-ferroelectric interfaces gives rise to a strong imprint where only one polarization orientation is favored, regardless of sign of external field. Asymmetrically distributed space charges may also lead to a single domain state in thin films with dead layers. The single-domain approximation for asymmetrical distributions of planar space charges is discussed.