Open AccessDepth‐dependent atomic valence determination by synchrotron techniques
Author(s) -
Trappen Robbyn,
Zhou Jinling,
Tra Vu Thanh,
Huang Chih-Yeh,
Dong Shuai,
Chu Ying-Hao,
Holcomb Mikel B.
Publication year - 2018
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s1600577518011724
Subject(s) - valence (chemistry) , x ray absorption spectroscopy , thin film , atomic layer deposition , materials science , analytical chemistry (journal) , chemistry , atomic physics , absorption spectroscopy , nanotechnology , optics , physics , organic chemistry , chromatography
The properties of many materials can be strongly affected by the atomic valence of the contained individual elements, which may vary at surfaces and other interfaces. These variations can have a critical impact on material performance in applications. A non‐destructive method for the determination of layer‐by‐layer atomic valence as a function of material thickness is presented for La 0.7 Sr 0.3 MnO 3 (LSMO) thin films. The method utilizes a combination of bulk‐ and surface‐sensitive X‐ray absorption spectroscopy (XAS) detection modes; here, the modes are fluorescence yield and surface‐sensitive total electron yield. The weighted‐average Mn atomic valence as measured from the two modes are simultaneously fitted using a model for the layer‐by‐layer variation of valence based on theoretical model Hamiltonian calculations. Using this model, the Mn valence profile in LSMO thin film is extracted and the valence within each layer is determined to within an uncertainty of a few percent. The approach presented here could be used to study the layer‐dependent valence in other systems or extended to different properties of materials such as magnetism.