Local structure analysis of dilute dopants in ceramics
Inquiry number
SOL-0000001063
Beamline
BL01B1 (XAFS I)
Scientific keywords
A. Sample category | inorganic material |
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B. Sample category (detail) | insulator, ceramics, amorphous, glass |
C. Technique | absorption and its secondary process |
D. Technique (detail) | XAFS, XANES |
E. Particular condition | polarization (linear), room temperature |
F. Photon energy | X-ray (4-40 keV) |
G. Target information | chemical state, chemical bonding, local structure, function and structure, function, electronic state |
Industrial keywords
level 1---Application area | electric component, display, cell (battery), Chemical product, industrial material |
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level 2---Target | condenser, LCD, PDP、FED, CD-R、DVD, fuel cell, catalysis, fiber |
level 3---Target (detail) | phosphor |
level 4---Obtainable information | local structure, electronic state, valence |
level 5---Technique | XAFS, NEXAFS |
Classification
A80.30 inorganic material, M40.10 XAFS
Body text
In this solution, fluorescence XANES method at Ga K-edge was applied to study local environments of ultra dilute Ga dopants (30 ppm) in MgO ceramics. For dilute samples, the fluorescence XANES method is a powerful technique to study local electronic structure (valence, species of neighbor atoms) of selected elements. XANES analysis using first-principles calculations revealed that Ga atom substitutes on a Mg site and extra charges are compensated by formation of a Mg vacancy as shown in model 3.
Fig. Ga K-edge XANES spectra of Ga dopants in MgO ceramics and structural model (red square: Ga, gray: Mg, white circle: O, red circle: Mg vacancy)
[ I. Tanaka, T. Mizoguchi, M. Matsui, S. Yoshioka, H. Adachi, T. Yamamoto, T. Okajima, N. Umesaki, W.-Y. Ching, Y. Inoue, M. Mizuno, H. Araki and Y. Shirai, Nature Materials 2, 541-545 (2003), Fig. 2,
©2003 Nature Publishing group ]
Source of the figure
Bulletin from SPring-8
Bulletin title
SPring-8 Research Fronties 2003
Page
78
Technique
XAFS spectra of dilute samples are taken by fluorescence XAFS method. This method is performed by measuring fluorescence from excited atoms as a function of x-ray energy around an absorption edge of a selected element. A 19-element Ge detector is used for measurement of 1-1000 ppm samples. Acquisition time per XANES spectrum is 15-30 min in this solution. Multi-scattering calculations and first-principle calculations have been successfully applied to the analysis of XANES spectra recently.
Source of the figure
No figure
Required time for experimental setup
4 hour(s)
Instruments
Instrument | Purpose | Performance |
---|---|---|
XAFS Measurement System | Measurement of XAFS spectra | 3.8-113 keV |
19 Ge Detector | Measurement of XAFS spectra of dilute sample and thin film | concentration: 1-1000 ppm, thickness > 0.1 nm |
References
Document name |
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I. Tanaka et al., Nature Materials, 2, 541(2003) |
Related experimental techniques
Questionnaire
This solution is an application of a main instrument of the beamline.
Ease of measurement
Middle
Ease of analysis
With a great skill
How many shifts were needed for taking whole data in the figure?
Less than one shift