Voltage and partial pressure dependent defect chemistry in (La,Sr)FeO3−δ thin films investigated by chemical capacitance measurements,Physical Chemistry Chemical Physics

当前位置： X-MOL 学术 › Phys. Chem. Chem. Phys. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Voltage and partial pressure dependent defect chemistry in (La,Sr)FeO3−δ thin films investigated by chemical capacitance measurements
Physical Chemistry Chemical Physics ( IF 2.9 ) Pub Date : 2018-04-05 00:00:00 , DOI: 10.1039/c7cp07845e
Alexander Schmid _{1,

2,

3} , Ghislain M. Rupp _{1,

2,

3} , Jürgen Fleig _{1,

2,

3}

Affiliation

La_0.6Sr_0.4FeO_3−δ (LSF) thin films of different thickness were prepared by pulsed laser deposition on yttria stabilized zirconia (YSZ) and characterized by using three electrode impedance spectroscopy. Electrochemical film capacitance was analyzed in relation to oxygen partial pressure (0.25 mbar to 1 bar), DC polarization (0 m to −600 m) and temperature (500 to 650 °C). For most measurement parameters, the chemical bulk capacitance dominates the overall capacitive properties and the corresponding defect chemical state depends solely on the oxygen chemical potential inside the film, independent of atmospheric oxygen pressure and DC polarization. Thus, defect chemical properties (defect concentrations and defect formation enthalpies) could be deduced from such measurements. Comparison with LSF defect chemical bulk data from the literature showed good agreement for vacancy formation energies but suggested larger electronic defect concentrations in the films. From thickness-dependent measurements at lower oxygen chemical potentials, an additional capacitive contribution could be identified and attributed to the LSF|YSZ interface. Deviations from simple chemical capacitance models at high pressures are most probably due to defect interactions.

中文翻译：

电压和分压取决于缺陷化学中（LA，SR）的FeO _{3- δ}薄膜调查通过化学电容测量

La _0.6 Sr _0.4 FeO _{3− δ}通过在氧化钇稳定的氧化锆（YSZ）上进行脉冲激光沉积制备了不同厚度的（LSF）薄膜，并通过三电极阻抗谱对其进行了表征。分析了与氧气分压（0.25 mbar至1 bar），DC极化（0 m至-600 m）和温度（500至650°C）有关的电化学膜电容。对于大多数测量参数而言，化学体积电容在总体电容性质中占主导地位，相应的缺陷化学状态仅取决于薄膜内部的氧化学势，而与大气氧压和DC极化无关。因此，可以从这样的测量中推导出缺陷化学性质（缺陷浓度和缺陷形成焓）。与文献中的LSF缺陷化学体数据比较表明，空位形成能具有很好的一致性，但表明薄膜中的电子缺陷浓度较高。通过在较低的氧气化学势下进行取决于厚度的测量，可以识别出其他电容贡献并将其归因于LSF | YSZ界面。高压下简单化学电容模型的偏差很可能是由于缺陷相互作用所致。

更新日期：2018-04-05

点击分享查看原文

点击收藏

公开下载

阅读更多本刊最新论文本刊介绍/投稿指南11