Surface Termination Conversion during SrTiO3 Thin Film Growth Revealed by X-ray Photoelectron Spectroscopy

被引：34

作者：

Baeumer, Christoph ^{[1
,2
]}

Xu, Chencheng ^{[1
,2
]}

Gunkel, Felix ^{[1
,2
,3
]}

Raab, Nicolas ^{[1
,2
]}

Heinen, Ronja Anika ^{[1
,2
]}

Koehl, Annemarie ^{[1
,2
]}

Dittmann, Regina ^{[1
,2
]}

机构：

[1] Forschungszentrum Julich, Peter Gruenberg Inst, D-52425 Julich, Germany

[2] Forschungszentrum Julich, JARA FIT, D-52425 Julich, Germany

[3] Rhein Westfal TH Aachen, Inst Werkstoffe Elektrotech 2, D-52074 Aachen, Germany

来源：

SCIENTIFIC REPORTS | 2015年 / 5卷

关键词：

SUBSTRATE; INTERFACES;

D O I：

10.1038/srep11829

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

Emerging electrical and magnetic properties of oxide interfaces are often dominated by the termination and stoichiometry of substrates and thin films, which depend critically on the growth conditions. Currently, these quantities have to be measured separately with different sophisticated techniques. This report will demonstrate that the analysis of angle dependent X-ray photoelectron intensity ratios provides a unique tool to determine both termination and stoichiometry simultaneously in a straightforward experiment. Fitting the experimental angle dependence with a simple analytical model directly yields both values. The model is calibrated through the determination of the termination of SrTiO3 single crystals after systematic pulsed laser deposition of sub-monolayer thin films of SrO. We then use the model to demonstrate that during homoepitaxial SrTiO3 growth, excess Sr cations are consumed in a self-organized surface termination conversion before cation defects are incorporated into the film. We show that this termination conversion results in insulating properties of interfaces between polar perovskites and SrTiO3 thin films. These insights about oxide thin film growth can be utilized for interface engineering of oxide heterostructures. In particular, they suggest a recipe for obtaining two-dimensional electron gases at thin film interfaces: SrTiO3 should be deposited slightly Ti-rich to conserve the TiO2-termination.

引用

页数：11

共 34 条

[11] Critical thickness and orbital ordering in ultrathin La0.7Sr0.3MnO3 films [J].

Huijben, M. ;

Martin, L. W. ;

Chu, Y. -H. ;

Holcomb, M. B. ;

Yu, P. ;

Rijnders, G. ;

Blank, D. H. A. ;

Ramesh, R. .

PHYSICAL REVIEW B, 2008, 78 (09)

[12]

Hwang HY, 2012, NAT MATER, V11, P103, DOI [10.1038/NMAT3223, 10.1038/nmat3223]

[13] Nonstoichiometry accommodation in SrTiO3 thin films studied by positron annihilation and electron microscopy [J].

Keeble, D. J. ;

Wicklein, S. ;

Jin, L. ;

Jia, C. L. ;

Egger, W. ;

Dittmann, R. .

PHYSICAL REVIEW B, 2013, 87 (19)

[14] Quasi-ideal strontium titanate crystal surfaces through formation of strontium hydroxide [J].

Koster, G ;

Kropman, BL ;

Rijnders, GJHM ;

Blank, DHA ;

Rogalla, H .

APPLIED PHYSICS LETTERS, 1998, 73 (20) :2920-2922

[15] The metallic interface between insulating NdGaO3 and SrTiO3 perovskites [J].

Li, Chen ;

Xu, Qinfang ;

Wen, Zheng ;

Zhang, Shantao ;

Li, Aidong ;

Wu, Di .

APPLIED PHYSICS LETTERS, 2013, 103 (20)

[16] Fabricating superconducting interfaces between artificially grown LaAlO3 and SrTiO3 thin films [J].

Li, Danfeng ;

Gariglio, Stefano ;

Cancellieri, Claudia ;

Fete, Alexandre ;

Stornaiuolo, Daniela ;

Triscone, Jean-Marc .

APL MATERIALS, 2014, 2 (01)

[17] Why some interfaces cannot be sharp [J].

Nakagawa, N ;

Hwang, HY ;

Muller, DA .

NATURE MATERIALS, 2006, 5 (03) :204-209

[18] Atomically precise interfaces from non-stoichiometric deposition [J].

Nie, Y. F. ;

Zhu, Y. ;

Lee, C. -H. ;

Kourkoutis, L. F. ;

Mundy, J. A. ;

Junquera, J. ;

Ghosez, Ph. ;

Baek, D. J. ;

Sung, S. ;

Xi, X. X. ;

Shen, K. M. ;

Muller, D. A. ;

Schlom, D. G. .

NATURE COMMUNICATIONS, 2014, 5

[19] Nanoscale Laterally Modulated Properties of Oxide Ultrathin Films by Substrate Termination Replica through Layer-by-Layer Growth [J].

Ocal, Carmen ;

Bachelet, Romain ;

Garzon, Luis ;

Stengel, Massimiliano ;

Sanchez, Florencio ;

Fontcuberta, Josep .

CHEMISTRY OF MATERIALS, 2012, 24 (21) :4177-4184

[20] Preparation of thermally stable TiO2-terminated SrTiO3(100) substrate surfaces [J].

Ohnishi, T ;

Shibuya, K ;

Lippmaa, M ;

Kobayashi, D ;

Kumigashira, H ;

Oshima, M ;

Koinuma, H .

APPLIED PHYSICS LETTERS, 2004, 85 (02) :272-274

← 1 2 3 4 →