Improved cationic stoichiometry and insulating behavior at the interface of LaAlO3/SrTiO3 formed at high oxygen pressure during pulsed-laser deposition

被引：41

作者：

Kalabukhov, A. ^{[1
,4
]}

Boikov, Yu. A. ^{[2
]}

Serenkov, I. T. ^{[2
]}

Sakharov, V. I. ^{[2
]}

Borjesson, J. ^{[3
]}

Ljustina, N. ^{[3
]}

Olsson, E. ^{[3
]}

Winkler, D. ^{[1
]}

Claeson, T. ^{[1
]}

机构：

[1] Chalmers Univ Technol, Dept Microtechnol & Nanosci, MC2, S-41296 Gothenburg, Sweden

[2] RAS, AF Ioffe Physicotech Inst, St Petersburg, Russia

[3] Chalmers Univ Technol, Dept Appl Phys, S-41296 Gothenburg, Sweden

[4] Moscow MV Lomonosov State Univ, Skobeltsyn Inst Nucl Phys, Moscow, Russia

来源：

EPL | 2011年 / 93卷 / 03期

基金：

瑞典研究理事会;

关键词：

D O I：

10.1209/0295-5075/93/37001

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

Medium-energy ion spectroscopy, MEIS, and scanning transmission electron microscopy, STEM, were used to correlate the atomic structure of LaAlO3/SrTiO3 interfaces with their electrical properties. Interfaces were prepared at high (5x10(-2) mbar) and low (10(-4) mbar) oxygen pressure by pulsed-laser deposition. The high-oxygen-pressure heterostructures were insulating for all thicknesses while the low-oxygen-pressure ones became metallic for thicknesses above 4 unit cells. MEIS data show enhancement of the Sr surface peak and suppression of the La one in interfaces prepared at low oxygen pressure, which is interpreted as a La-Sr intermixing. The effect was considerably smaller in high-oxygen-pressure samples. Analysis of high-angle annular-dark-field STEM images of the LAO films also indicates intermixing between La and Sr in low-oxygen-pressure samples, supporting MEIS data. Our results reveal the important role of oxygen pressure on the formation of the interface electron gas. Copyright (C) EPLA, 2011

引用

页数：6

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