Microstructure, leakage current and dielectric tunability of Na0.5Bi0.5(Ti0.99Zn0.01)O-3 thin films: An annealing atmosphere-dependent study

摘要

Na0.5Bi0.5(Ti0.99Zn0.01)O-3 (NBTZn) thin films were deposited on the indium tin oxide (ITO)/glass substrates annealed under different atmospheres (air, N-2, O-2, O-2/N-2) via a metal organic decomposition process. The effects of annealing atmosphere on crystallization and electrical properties were mainly investigated. All the thin films exhibit single perovskite structures with predominant (110) orientation. Large grains are observed in N-2 due to the high content of oxygen vacancy. For the film annealed in O-2/N-2 atmosphere, the lower leakage current density and higher dielectric tunability can be obtained, which may be ascribed to the improvement of crystallization with more homogeneous grain sizes and dense microstructure. Also, the effects of measuring frequency on dielectric constant-electric field characteristic are discussed. A higher tunability of 47.6% and figure of merit of 7.9 at 300 kV/cm and 100 kHz for NBTZn film can be observed. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.