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Dielectric properties and energy storage capability of antiferroelectric Pb0.92La0.08Zr0.95Ti0.05O3 film-on-foil capacitors Beihai Ma,a) Do-Kyun Kwon,b) Manoj Narayanan, and U. (Balu) Balachandran Energy Systems Division, Argonne National Laboratory, Argonne, Illinois 60439 (Received 29 April 2009; accepted 17 June 2009)

Antiferroelectric (AFE) Pb0.92La0.08Zr0.95Ti0.05O3 (PLZT) films were grown on nickel foils with lanthanum nickel oxide buffer by chemical solution deposition. We observed field-induced AFE-to-ferroelectric (FE) phase transition. The electric field for the AFEto-FE phase transition (EAF
270 kV/cm) and that for the reverse phase transition (EFA
230 kV/cm) were measured at room temperature on samples with PLZT films of
1-mm thickness. Relative permittivity of
560 and dielectric loss of 5000 h when the capacitors are operated at room temperature with an applied field of
300 kV/cm. In recent years, increasing interest has been devoted to the development of antiferroelectric (AFE) ceramic films because of their anticipated high energy storage capabilities.1–8 The AFE ceramics are a subclass of dielectrics in which the orientations of the dipoles are alternately aligned in opposite directions, and no spontaneous polarization exists. Meanwhile, the AFE phase can be induced to the ferroelectric (FE) phase when the applied electric field is above a threshold electric field (EAF); the FE state can return to the AFE state when the field is decreased below a threshold electric field (EFA). An AFE material is characterized by double P-E hysteresis loops that are caused by a structural phase transformation induced by the external electric field. This phase transformation is accompanied by a large volume change and a significant increase in dielectric polarization.5–7 As a result, AFE material is capable of storing high electric energy density if it can sustain a large external field, i.e., exhibit high breakdown strength. The vast majority of AFE films are fabricated on single crystals or silicon wafers.3,9,10 However, the use of metallic substrates is potentially beneficial for the fabrication of large-area devices with low cost. Metal foils coated with dielectric material, the so-called “filmon-foil dielectric sheets,” could be laminated into printed circuit boards to create embedded capacitors that have a)

Address all correspondence to this author. e-mail: [email protected] b) Present address: Materials Engineering Department, Korea Aerospace University, Gyeonggi-do, Korea. DOI: 10.1557/JMR.2009.0349

broad applications in power electronics. We have determined that Pb0.92La0.08Zr0.95Ti0.05O3 (PLZT) film-onfoil capacitors exhibit promising dielectric properties and energy storage capability. Samples were prepared by a chemical solution deposition method. Prior to being coated, nickel substrates were polished with diamond paste to 1-mm finish, ultrasonically cleaned in distilled water, and then wipecleaned with acetone and methanol in sequence. The root-mean-square surface roughness of the polished substrate