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We demonstrate improvement in fatigue resistance and other ferroelectric properties through cerium doping in sol–gel derived lead zirconate titanate thin films. We have studied frequency dependence of fatigue behavior and show that the loss of polarization due to fatigue follows a universal scaling behavior with N/f2, where N is the number of switching cycles and f the frequency. The origin of the scaling is attributed to the drift of oxygen vacancies, which is the rate limiting process in the growth of the interface layer responsible for fatigue. Empirical fits for both undoped and cerium-doped samples show that switchable polarization follows stretched exponential decay with time or N/f. Cerium doping is shown to improve fatigue resistance by impeding the motion of oxygen vacancies.

Alternate layer deposition of heterostructured magnesium oxide (MgO):barium strontium titanate (BST) thin films is demonstrated to be an approach to synthesize dielectric films with a higher figure of merit for microwave dielectric applications. The dielectric constant and the dielectric tunability are modified by MgO insertion. The dramatic reduction in the dielectric loss tangent effectively increased the figure of merit of the heterostructured thin films as compared to the pure BST films. The significant reduction in the dielectric loss tangent values has been attributed to the minute solid solubility of MgO in the BST lattice and the induced microstructural modifications induced by the MgO layers in thin films.