Effect of CaRuO3 interlayer on the dielectric properties of Ba(Zr,Ti)O3 thin films prepared by pulsed laser deposition

Ba(Zr0.2Ti0.8)O3 (BZT) thin films on Pt(111)∕Ti∕SiO2∕Si(100) substrates without and with CaRuO3 (CRO) buffer layer were fabricated at 650°C in situ by pulsed laser deposition. The BZT thin films showed a dense morphology, many clusters are found on the surface images of BZT/Pt films, which are composed by nanosized grains of 25–35nm; the average grain size of BZT/CRO films is about 80nm, which lager than that of BZT/Pt thin film. The dielectric constants and dissipation factors of BZT/Pt and BZT/CRO thin films were 392 and 0.019 and 479 and 0.021 at 1MHz, respectively. The dielectric constant of BZT/Pt and BZT/CRO thin films changes significantly with applied dc bias field and has high tunabilities and figures of merit of ∼70% and 37 and 75% and 36, respectively, under an applied field of 400kV∕cm. The possible microstructural background responsible for the high dielectric constant and tunability was discussed.