ScholarWorks@성균관대학교

초록

Many ferroelectrics, such as lead zirconate titanate, are widely known to exhibit excellent ferroelectric and piezoelectric properties near the morphotropic phase boundary (MPB), where two phases coexist in a solid solution form. Nano-clustering by aerosol deposition (AD) enables multiphase films to be prepared from distinct phases at room temperature. Herein, nano-clustered (NC) antiferroelectric xPbZrO3 (PZ) - ferroelectric (1-x)PbTiO3 (PT) films are fabricated to assess the possibility for artificial MPB (aMPB) behavior. This is done by comparing the composition-dependent ferroelectric and piezoelectric properties with those of solid solution (SS) Pb(Zrx,Ti1-x)O3 (PZT) films. The origin of the aMPB behavior in the NC PZ-PT film is verified through phase field modeling to be the internal local depolarization field generated in AFE. Both the SS PZT film and the NC PZ-PT film exhibited the largest dielectric constants (epsilon r) of 820 and 650, and large signal piezoelectric constant (d33,f*) of 86 and 82 pm V-1, respectively, at a near-MPB composition (x = 0.5) compared to those of the Ti-rich (x = 0.1) and Zr-rich (x = 0.9) compositions, indicating aMPB behavior. The aMPB behavior induced by the nano-clustering is expected to be expanded to combinations of various material compositions that do not form solid solutions.

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