Previous XAFS Work on BaTiO3

X-ray Absorption Fine Structure (XAFS) provides a direct measurement of the local structure in BaTiO3. Specifically, XAFS may be used to distinguish between order--disorder and displacive models for the local structure. XAFS is particularly well suited to this problem as it offers Ångstrom spatial resolution combined with femtosecond temporal resolution.[1]

By measuring the the Ba K edge Extended X-ray Absorption Fine Structure (EXAFS) and Ti K edge X-ray Absorption Near Edge Structure (XANES) of BaTiO3, I determined that the local structure about the Ti atom in BaTiO3 remains rhombohedrally distorted throughout its various phase transitions.[2]

This result is more consistent with the eight-site, order-disorder model of Comes et al. [3] than with a displacive model which predicts that the local symmetry about the Ti atom reflects the symmetry of the macroscopic structure.

For a fully quantitative results, analysis of the Ti K edge EXAFS is required.

 

But...

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Bruce Ravel

Last modified: Wed Feb 18 15:56:11 EST 1998