Temperature- and frequency-dependent dielectric behavior in epitaxial CaSnO₃ films

We systematically examine the dielectric response of epitaxial CaSnO₃ films grown by hybrid molecular beam epitaxy. Metal-insulator-metal capacitor structures consisting of Nb:SrTiO₃ (001)/t-nm CaSnO₃/100-nm Pt (top electrode) were fabricated to characterize the dielectric properties of CaSnO₃, including the dielectric constant (κ) and loss tangent across wide temperature (1.8-400 K) and frequency ranges (20 Hz-1 MHz). Films exhibited a dielectric constant of ∼17 and a low loss tangent (<0.02), independent of thickness and electrode geometry. The minimal variation with temperature and frequency highlights CaSnO₃'s potential as a robust, low-loss, high-κ dielectric for advanced oxide electronics and gate insulator applications.