High permittivity 0.9Pb(Mg1/3Nb2/3)O3-0.1PbTiO3 relaxor thin films for high-value, wide-temperature capacitor applications

High permittivity 0.9Pb(Mg1/3Nb2/3)O3-0.1PbTiO3 (PMNT) relaxor thin films with a nearly pure perovskite structure as well as a dense and uniform microstructure have been prepared on Pb(Zr,Ti)O3-buffered platinized silicon substrates by sol-gel method. Interestingly, the PMNT thin film exhibits high dielectric permittivity, er ∼ 1200, and high dielectric tunability, ∼70% under a moderate E = 333 kV/cm, over a wide temperature range. These results are explained in terms of a relaxor behavior of the PMNT film. Moreover, the leakage current density of the PMNT thin film is reasonably low, roughly 5.2 × 10−6 A/cm2 at an electric field intensity of 400 kV/cm. As the dc electric field increases, the leakage current mechanism is transformed from ohmic law to Fowler–Nordheim tunneling mechanism. All the results obtained indicate that the PMNT relaxor thin film is a good candidate for high-value, wide-temperature capacitor applications.