Strain Tuning of Ferroelectric Thin Films

Predictions and measurements of the effect of biaxial strain on the properties of epitaxial ferroelectric thin films and superlattices are reviewed. Results for single-layer ferroelectric films of biaxially strained SrTiO 3 , BaTiO 3 , and PbTiO 3 as well as PbTiO 3 /SrTiO 3 and BaTiO 3 /SrTiO 3 superlattices are described. Theoretical approaches, including first principles, thermodynamic analysis, and phase-field models, are applied to these biaxially strained materials, the assumptions and limitations of each technique are explained, and the predictions are compared. Measurements of the effect of biaxial strain on the paraelectric-to-ferroelectric transition temperature (T C ) are shown, demonstrating the…