Local structure in LaMnO{sub 3} and CaMnO{sub 3} perovskites: A quantitative structural refinement of Mn K-edge XANES data
- Dipartimento di Fisica Universita di 'Roma Tre', Via della Vasca Navale 84, I-00146 Rome (Italy)
- INFN Laboratori Nazionali di Frascati, Via E. Fermi 40, I-00044 Frascati (Italy)
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012 (India)
Hole-doped perovskites such as La{sub 1-x}Ca{sub x}MnO{sub 3} present special magnetic and magnetotransport properties, and it is commonly accepted that the local atomic structure around Mn ions plays a crucial role in determining these peculiar features. Therefore experimental techniques directly probing the local atomic structure, like x-ray absorption spectroscopy (XAS), have been widely exploited to deeply understand the physics of these compounds. Quantitative XAS analysis usually concerns the extended region [extended x-ray absorption fine structure (EXAFS)] of the absorption spectra. The near-edge region [x-ray absorption near-edge spectroscopy (XANES)] of XAS spectra can provide detailed complementary information on the electronic structure and local atomic topology around the absorber. However, the complexity of the XANES analysis usually prevents a quantitative understanding of the data. This work exploits the recently developed MXAN code to achieve a quantitative structural refinement of the Mn K-edge XANES of LaMnO{sub 3} and CaMnO{sub 3} compounds; they are the end compounds of the doped manganite series La{sub x}Ca{sub 1-x}MnO{sub 3}. The results derived from the EXAFS and XANES analyses are in good agreement, demonstrating that a quantitative picture of the local structure can be obtained from XANES in these crystalline compounds. Moreover, the quantitative XANES analysis provides topological information not directly achievable from EXAFS data analysis. This work demonstrates that combining the analysis of extended and near-edge regions of Mn K-edge XAS spectra could provide a complete and accurate description of Mn local atomic environment in these compounds.
- OSTI ID:
- 20719775
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Vol. 72, Issue 17; Other Information: DOI: 10.1103/PhysRevB.72.174104; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION SPECTRA
ABSORPTION SPECTROSCOPY
CALCIUM COMPOUNDS
CRYSTAL STRUCTURE
DATA ANALYSIS
DOPED MATERIALS
ELECTRONIC STRUCTURE
FINE STRUCTURE
HOLES
LANTHANUM COMPOUNDS
MANGANATES
MANGANESE IONS
PEROVSKITES
TOPOLOGY
X-RAY SPECTROSCOPY