Stoichiometry of LaAlO3 films grown on SrTiO3 by pulsed laser deposition

被引：23

作者：

Golalikhani, M. ^{[1
]}

Lei, Q. Y. ^{[1
]}

Chen, G. ^{[2
]}

Spanier, J. E. ^{[2
]}

Ghassemi, H. ^{[2
]}

Johnson, C. L. ^{[2
]}

Taheri, M. L. ^{[2
]}

Xi, X. X. ^{[1
]}

机构：

[1] Temple Univ, Dept Phys, Philadelphia, PA 19122 USA

[2] Drexel Univ, Dept Mat Sci & Engn, Philadelphia, PA 19104 USA

来源：

JOURNAL OF APPLIED PHYSICS | 2013年 / 114卷 / 02期

基金：

美国国家科学基金会;

关键词：

OXIDE HETEROSTRUCTURES; INTERFACES; DISPLACEMENT;

D O I：

10.1063/1.4811821

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

We have studied the stoichiometry of epitaxial LaAlO3 thin films on SrTiO3 substrate grown by pulsed laser deposition as a function of laser energy density and oxygen pressure during the film growth. Both x-ray diffraction (theta-2 theta scan and reciprocal space mapping) and transmission electron microscopy (geometric phase analysis) revealed a change of lattice constant in the film with the distance from the substrate. Combined with composition analysis using x-ray fluorescence we found that the nominal unit-cell volume expanded when the LaAlO3 film was La-rich, but remained near the bulk value when the film was La-poor or stoichiometric. La excess was found in all the films deposited in oxygen pressures lower than 10(-2) Torr. We conclude that the discussion of LaAlO3/SrTiO3 interfacial properties should include the effects of cation off-stoichiometry in the LaAlO3 films when the deposition is conducted under low oxygen pressures. (C) 2013 AIP Publishing LLC.

引用

页数：5

共 26 条

[1] Mapping the spatial distribution of charge carriers in LaAlO3/SrTiO3 heterostructures [J].