Depth-dependent atomic valence determination by synchrotron techniques
- Resource Type
- Authors
- Chih Yeh Huang; Vu Thanh Tra; Shuai Dong; Mikel B. Holcomb; Ying-Hao Chu; Robbyn Trappen; Jinling Zhou
- Source
- Journal of Synchrotron Radiation. 25:1711-1718
- Subject
- Nuclear and High Energy Physics
X-ray absorption spectroscopy
Radiation
Materials science
Valence (chemistry)
Absorption spectroscopy
Magnetism
02 engineering and technology
021001 nanoscience & nanotechnology
01 natural sciences
Synchrotron
law.invention
symbols.namesake
law
0103 physical sciences
symbols
Thin film
Atomic physics
010306 general physics
0210 nano-technology
Material properties
Hamiltonian (quantum mechanics)
Instrumentation
- Language
- ISSN
- 1600-5775
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 La0.7Sr0.3MnO3 (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.