Effect of Nb doping on preferential orientation, phase transformation behavior and electrical properties of PbZrO3 thin films

Undoped and Nb-doped (1, 3, 5, 7 and 9 mol%) PbZrO3 antiferroelectric thin films were deposited on Pt(1 1 1)/Ti/SiO2/Si substrates by using a sol–gel method. All the thin films had a perovskite phase structure and exhibited a distinct preferential orientation, phase transformation behavior and electrical properties, due to the effect of Nb doping. On the extent of Nb dopant, orientation of the films was changed from (1 0 0) to (1 1 1) gradually. Meanwhile, with increasing Nb content, a gradual change from AFE to ferroelectric at room temperature was observed. Dielectric constant as a function of Nb content was also reported. The dielectric constant increased with Nb content up to 7 mol% and then decreased at 9 mol% Nb. Dielectric loss remained quite low (less than 0.05) in the whole frequency or voltage ranges.

► (1 1 1)-Preferred orientation enhances with increasing Nb content.
► On extent of Nb dopant the films experience a transformation from AFE to FE phase.
► The diffusing phase transformation character enhances with increasing Nb content.
► The largest ɛ for the films with 7 mol% Nb-doping.