Produção Nacional
Disorder-induced symmetry lowering in the CsInMgF 6 pyrochlore crystal
2002; American Physical Society; Volume: 66; Issue: 21 Linguagem: Inglês
10.1103/physrevb.66.214105
ISSN1095-3795
AutoresAlejandro Pedro Ayala, C. W. A. Paschoal, I. Guedes, Waldeci Paraguassu, Paulo Freire, J. Mendes Fílho, Roberto L. Moreira, J.Y. Gesland,
Tópico(s)Multiferroics and related materials
ResumoPolarized Raman scattering and infrared reflectivity of the modified pyrochlore single crystal ${\mathrm{CsInMgF}}_{6}$ have been carried out at room temperature. The spectra showed the appearance of additional Raman and infrared bands, which are not predicted from group theory for the pyrochlore cubic structure. A deeper analysis, by taking into account the occupational disorder of ${\mathrm{Mg}}^{2+}$ and ${\mathrm{In}}^{3+}$ in octahedral sites, indicates that the overall features can be explained by a lowering of the crystal symmetry from $F3\overline{d}m$ ${(O}_{h}^{7})$ to $R3\ifmmode\bar\else\textasciimacron\fi{}m$ ${(D}_{3d}^{5}).$ This result should have important consequences on the understanding of the unusual magnetic behavior of this system.
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