Anomalous Interface and Surface Strontium Segregation in (La1-ySry)2CoO4±δ/La1-xSrxCoO3-δ Heterostructured Thin Films

被引：75

作者：

Feng, Zhenxing ^{[1
,2
]}

Yacoby, Yizhak ^{[4
]}

Gadre, Milind J. ^{[7
]}

Lee, Yueh-Lin ^{[1
,2
,7
]}

Hong, Wesley T. ^{[1
,3
]}

Zhou, Hua ^{[5
]}

Biegalski, Michael D. ^{[6
]}

Christen, Hans M. ^{[6
]}

Adler, Stuart B. ^{[8
]}

Morgan, Dane ^{[7
]}

Shao-Horn, Yang ^{[1
,2
,3
]}

机构：

[1] MIT, Electrochem Energy Lab, Cambridge, MA 02139 USA

[2] MIT, Dept Mech Engn, Cambridge, MA 02139 USA

[3] MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA

[4] Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel

[5] Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA

[6] Oak Ridge Natl Lab, Ctr Nanophase Mat Sci, Oak Ridge, TN 37831 USA

[7] Univ Wisconsin, Dept Mat Sci & Engn, Madison, WI 53706 USA

[8] Univ Washington, Dept Chem Engn, Seattle, WA 98195 USA

来源：

JOURNAL OF PHYSICAL CHEMISTRY LETTERS | 2014年 / 5卷 / 06期

基金：

以色列科学基金会;

关键词：

OXYGEN REDUCTION KINETICS; AB-INITIO; ELECTRONIC-STRUCTURE; CATION SEGREGATION; ATOMIC-STRUCTURE; OXIDE; ENHANCEMENT; PEROVSKITES; TRANSPORT; CATHODE;

D O I：

10.1021/jz500293d

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Heterostructured oxides have shown unusual electrochemical properties including enhanced catalytic activity, ion transport, and stability. In particular, it has been shown recently that the activity of oxygen electrocatalysis on the Ruddlesden-Popper/perovskite (La1-ySry)(2)CoO4 +/-delta/La1-xSrxCoO3-delta heterostructure is remarkably enhanced relative to the Ruddlesden-Popper and perovskite constituents. Here we report the first atomic-scale structure and composition of (La1-ySry)(2)CoO4 +/-delta/La1-xSrxCoO3-delta grown on SrTiO3. We observe anomalous strontium segregation from the perovskite to the interface and the Ruddlesden-Popper phase using direct X-ray methods as well as with ab initio calculations. Such Sr segregation occurred during the film growth, and no significant changes were found upon subsequent annealing in O-2. Our findings provide insights into the design of highly active catalysts for oxygen electrocatalysis.

引用

页码：1027 / 1034

页数：8

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