Author/Authors :
Ayala، نويسنده , , A.P. and Guedes Soares، نويسنده , , I. and Freire، نويسنده , , P.T.C. and Sasaki، نويسنده , , J.M. and Mendes Filho، نويسنده , , J. Y. Gesland، نويسنده , , J.Y. and Moreira، نويسنده , , R.L.، نويسنده ,
Abstract :
Li2MIIMIVF8 compounds have been suggested as good fluorine conductors, based on their crystalline structure. A careful experimental investigation using several techniques, including ac and dc electrical conductivity, calorimetric and Raman scattering measurements carried out on a Li2CaHfF8 crystal, leads us to propose a different structure for these compounds. This structure is compatible with the ionic conductivity and thermal behavior of our system. Also, piezoelectric resonances and Raman selection rules confirm our proposed non-centrosymmetrical group. A set of conduction mechanisms that describes the high anisotropic conductivity in the crystal is proposed.
