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.