Ionic Conductivity Increased by Two Orders of Magnitude in Micrometer-Thick Vertical Yttria-Stabilized ZrO2 Nanocomposite Films

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• 作者：Shinbuhm Lee ; Wenrui Zhang ; Fauzia Khatkhatay ; Haiyan Wang ; Quanxi Jia ; Judith L. MacManus-Driscoll
• 刊名：Nano Letters
• 出版年：2015
• 出版时间：November 11, 2015
• 年：2015
• 卷：15
• 期：11
• 页码：7362-7369
• 全文大小：515K
• ISSN：1530-6992

文摘

We design and create a unique cell geometry of templated micrometer-thick epitaxial nanocomposite films which contain 鈭?0 nm diameter yttria-stabilized ZrO₂ (YSZ) nanocolumns, strain coupled to a SrTiO₃ matrix. The ionic conductivity of these nanocolumns is enhanced by over 2 orders of magnitude compared to plain YSZ films. Concomitant with the higher ionic conduction is the finding that the YSZ nanocolumns in the films have much higher crystallinity and orientation, compared to plain YSZ films. Hence, 鈥渙xygen migration highways鈥?are formed in the desired out-of-plane direction. This improved structure is shown to originate from the epitaxial coupling of the YSZ nanocolumns to the SrTiO₃ film matrix and from nucleation of the YSZ nanocolumns on an intermediate nanocomposite base layer of highly aligned Sm-doped CeO₂ nanocolumns within the SrTiO₃ matrix. This intermediate layer reduces the lattice mismatch between the YSZ nanocolumns and the substrate. Vertical ionic conduction values as high as 10^鈥? 惟^鈥? cm^鈥? were demonstrated at 360 掳C (300 掳C lower than plain YSZ films), showing the strong practical potential of these nanostructured films for use in much lower operation temperature ionic devices.