Display options
Cite
Piovano A, Ceretti M, Johnson MR, et al. Anisotropy in the Raman scattering of a CaFeO2.5 single crystal and its link with oxygen ordering in Brownmillerite frameworks. J Phys Condens Matter. 2015;27(22):225403doi: 10.1088/0953-8984/27/22/225403.
Piovano, A., Ceretti, M., Johnson, M. R., Agostini, G., Paulus, W., & Lamberti, C. (2015). Anisotropy in the Raman scattering of a CaFeO2.5 single crystal and its link with oxygen ordering in Brownmillerite frameworks. Journal of physics. Condensed matter : an Institute of Physics journal, 27(22), 225403. https://doi.org/10.1088/0953-8984/27/22/225403
Piovano, Andrea, et al. "Anisotropy in the Raman scattering of a CaFeO2.5 single crystal and its link with oxygen ordering in Brownmillerite frameworks." Journal of physics. Condensed matter : an Institute of Physics journal vol. 27,22 (2015): 225403. doi: https://doi.org/10.1088/0953-8984/27/22/225403
Piovano A, Ceretti M, Johnson MR, Agostini G, Paulus W, Lamberti C. Anisotropy in the Raman scattering of a CaFeO2.5 single crystal and its link with oxygen ordering in Brownmillerite frameworks. J Phys Condens Matter. 2015 Jun 10;27(22):225403. doi: 10.1088/0953-8984/27/22/225403. Epub 2015 May 19. PMID: 25989601.
Copy Download .nbib Format: NLM
Share it on

J Phys Condens Matter. 2015 Jun 10;27(22):225403. doi: 10.1088/0953-8984/27/22/225403. Epub 2015 May 19.

Anisotropy in the Raman scattering of a CaFeO2.5 single crystal and its link with oxygen ordering in Brownmillerite frameworks.

Journal of physics. Condensed matter : an Institute of Physics journal

Andrea Piovano, Monica Ceretti, Mark R Johnson, Giovanni Agostini, Werner Paulus, Carlo Lamberti

Affiliations

  1. Institut Laue-Langevin (ILL), 71 avenue des Martyrs, 38000 Grenoble, France.

PMID: 25989601 DOI: 10.1088/0953-8984/27/22/225403

Abstract

Periodic DFT calculations allow an understanding of the strong orientation-dependent Raman spectra of oriented CaFeO2.5 single crystals. Modes involving the oscillation of the apical oxygen (O(ap)) atoms perturb the induced electric dipoles. These are formed by anisotropy in the charge distribution and are found to be strongly enhanced when the electric field of the linearly polarized laser line is parallel to the b axis. For the CaFeO2.5 ordered system, strong polarizability of these modes corresponds to strong Raman intensities. Conversely, the apical oxygen disorder observed in low-temperature oxygen-conducting SrFeO2.5 destroys the long-range coherence of the respective Raman modes, which consequently show a strongly reduced intensity. This study provides a vibrational tool to discriminate between ordered and disordered isomorporphous ABO2.5 Brownmillerite frameworks. Furthermore, in combination with DFT calculations, we have found that the weakening of the interlayer interactions is responsible for the loss of ordering in Brownmillerite compounds.

Publication Types