Investigation of bulk and interfacial properties of Ba0.5Sr0.5TiO3 thin film capacitors

Abstract

In this letter, we report the results for capacitance versus frequency measurements on a set of Ba0.5Sr0.5TiO3 (BST) capacitors with platinum electrodes (Pt) and varying BST film thicknesses. The study shows that Pt/BST interfacial capacitance is independent of frequency whereas the bulk dielectric constant has a power law dependence on frequency. Also, the bulk dielectric constant is observed to decrease whereas the interfacial capacitance increases with increasing temperature. In addition, we report the dependence of dielectric dispersion on BST film thickness and temperature. Calculations are performed which provide insights into the observed dispersion effects.