Espalhamento Raman dependente da temperatura no condutor superionico B-Eucrypte

AUTOR(ES)
DATA DE PUBLICAÇÃO

1980

RESUMO

By using Raman scattering techniques, we have studied the normal modes of vibration and the dynamics of the ionic motion in the superionic conductor b-Eucryptite, as a function of temperature, from room temperature to ~ 750ºC. Our results have proved that the high ionic conductivity it displays (~ 10-2 W-1cm-1, at 600ºC), can be explained in terms of the highly correlatet Li+ motions, brought about by the structure channels and by the disordered distribution of these ions in high temperatures. This high ionic conductivity is achieved via a gradual order-disorder phase transition which takes place at the 500-600ºC range of temperatures. As the structure of the b-Eucryptite shows simililarities to quartz, the phonon frequencies in both crystals are nearly the same. However, since the b-Eucryptite Brillouin zone is halved compared with that of quartz, phonons characteristic of critical points in quartz are Raman active in b-Eucryptite, Furthermore we have noted the appearance of extra features in Raman spectra of b-Eucryptite, attributed to vibrational and diffusive motions of Li+ ions

ASSUNTO(S)

raman efeito de espalhamento (fisica)

ACESSO AO ARTIGO

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