Crossover Between Extrinsic and Intrinsic Dielectric Loss Mechanisms in SrTiO3 Thin Films at Microwave Frequencies

At microwave frequencies SrTiO ₃ thin films, which shows a crossover between extrinsic and intrinsic dielectric loss mechanism was analyzed. The experimental data suggest the strong occurrence of a cossover in the dominant loss mechanism. It was found that the loss is governed by an extrinsic mechanism at weak fields while, at higher fields, the contribution of an intrinsic mechanism becomes predominant. Results suggests that the quality of tunable ferroelectric films can be measured from the shape of the field dependence of the loss tangent.