Leakage current characteristics and dielectric breakdown of antiferroelectric Pb0.92La0.08Zr0.95Ti0.05O3 film capacitors grown on metal foils

We have grown crack-free antiferroelectric (AFE) Pb0.92La0.08Zr0.95Ti0.05O3 (PLZT) films on nickel foils by chemical solution deposition. To eliminate the parasitic effect caused by the formation of a low-permittivity interfacial oxide, we applied a conductive buffer layer of lanthanum nickel oxide (LNO) on the nickel foil by chemical solution deposition prior to the PLZT deposition. Use of the LNO buffer allowed high-quality film-on-foil capacitors to be prepared at high temperatures in air. With the AFE PLZT deposited on LNO-buffered Ni foils, we observed field-induced phase transformations of AFE to ferroelectric (FE). The AFE-to-FE phase transition field, EAF = 260 kV cm-1, and the reverse phase transition field, EFA = 220 kV cm-1, were measured at room temperature on a ∼1.15 μm thick PLZT film grown on LNO-buffered Ni foils. The relative permittivities of the AFE and FE states were ∼530 and ∼740, respectively, with dielectric loss <0.05 at room temperature. P-E hysteresis loop measured at room temperature confirmed the field-induced phase transition. The time-relaxation current density was investigated under various applied electric fields. The leakage current density of a 1.15 μm thick AFE PLZT film-on-foil capacitor was 5 x 10-9 A cm-2 at room temperature under 87 kV cm-1 applied field. The breakdown behaviour of the AFE PLZT film-on-foil capacitors was studied by Weibull analysis. The mean breakdown time decreased exponentially with increasing applied field. The mean breakdown time was over 610 s when a field of 1.26 MV cm-1 was applied to a 1.15 μm thick AFE PLZT film-on-foil capacitor.