Nonlinear polarization responses of ZrO2-based thin films fabricated by chemical solution deposition

The nonlinear polarization responses of ZrO2-based thin films were investigated. Y, Ce, Ti, and Sn were used as substitutes in ZrO2 thin films by chemical solution deposition. A pure ZrO2 film and the ZrO2 film with 1% Y substitution showed constricted polarization-electric field (P-E) curves. In contrast, the ZrO2 film with 5% Y substitution showed a linear P-E curve. The dielectric constants of the pure ZrO2 film and the ZrO2 film with 1% Y substitution increased by 7 and 11%, respectively, under an applied electric field of 2.5 MV/cm. The nonlinearity of the polarization responses was decreased by Ce substitution and Ti substitution. The ZrO2 films with Sn substitution showed narrow P-E curves. The dielectric constant of the ZrO2 film with 10% Sn substitution increased by 13% under an applied electric field of 3 MV/cm. These dielectric constant increases originate from electric-field-induced phase transitions of ZrO2-based thin films. (C) 2017 The Japan Society of Applied Physics