Dielectric properties of Nb-doped PbZrO₃ thin films prepared by pulsed laser deposition

The preparation of Nb-doped PbZrO₃ thin films by pulsed laser deposition and the effects of the Nb-doping on the dielectric properties of PbZrO₃ thin films have been investigated. By optimizing film deposition conditions and annealing temperatures, the 3 mol% Nb-doped PbZrO₃ thin films was successfully prepared under the partial oxygen pressure of 2 or 5 Pa followed by the rapid thermal annealing at 873 K for 1 min. From X-ray diffractometry, the PbZrO₃ phase was found to be crystallized without any preferred orientation. The 3 mol% Nb-doped PbZrO₃ film exhibited a double hysteresis loop with a transition field (antiferroelecric to ferrcelectric phase) of 208×10⁵ V/m and saturation polarization of 20×10^-2 C/m². It was found that the Nb-doping might contribute to reduce the transition field and polarization of PbZrO₃ thin films. In addition, the Nb-doped PbZrO₃ film with a thickness of 185 nm showed a ferroelectric hysteresis loop with the parameters of Ps = 22×10^-2 C/m², Pr = 17×10^-2 C/m² and Ec = 320×10⁵ V/m.