Composition, Ion-Ion Correlations, and Conductivity of Beta-Alumina

摘要

It is concluded from conductivity and diffuse x-ray scattering measurements on Mg stabilized Na an K beta -alumina single crystals that higher activation energies are associated with greater ordering of mobile ions on a superlattice. Similar measurements on Zn stabilized Na beta with a higher vacancy concentration suggest that the low temperature conductivity is mainly determined by the fraction of vacancies that are not ordered. The rapid decrease observed in the Raman intensity of the 144cm exp -1 Na+ mode with increasing temperature is attributed to fluctuations caused by thermal excitation of the low energy mode at 32 cm exp -1 . (ERA citation 07:054435)