Structural and dielectric behavior of pulsed laser ablated Sr0.6Ca0.4TiO3 thin film and asymmetric multilayer of SrTiO3 and CaTiO3

Abstract: Homogeneous thin films of Sr0.6Ca0.4TiO3 (SCT40) and asymmetric multilayer of SrTiO3 (STO) and CaTiO3 (CTO) were fabricated on Pt/Ti/SiO2/Si substrates by using pulsed laser deposition technique. The electrical behavior of films was observed within a temperature range of 153K–373K. A feeble dielectric peak of SCT40 thin film at 273K is justified as paraelectric to antiferroelectric phase transition. Moreover, the Curie–Weiss temperature, determined from the ε′(T) data above the transition temperature is found to be negative. Using Landau theory, the negative Curie–Weiss temperature is interpreted in terms of an antiferroelectric transition. The asymmetric multilayer exhibits a broad dielectric peak at 273K, and is attributed to interdiffusion at several interfaces of multilayer. The average dielectric constants for homogeneous Sr0.6Ca0.4TiO3 films (∼650) and asymmetric multilayered films (∼350) at room temperature are recognized as a consequence of grain size effect. Small frequency dispersion in the real part of the dielectric constants and relatively low dielectric losses for both cases ensure high quality of the films applicable for next generation integrated devices. [Copyright &y& Elsevier]