Mixed conduction of lithium vanadium tellurite glasses

The effect of Li2O on the electrical conductivity of vanadium tellurite gla sses has been studied by using impedance spectroscopy over a wide range of temperatures. The results obtained confirm the existence of a transition fr om a typically electronic (polaronic) conductive regime when the molar frac tion (X) of Li2O is equal to 0, to an ionic conductive regime when X tends to 1. This transition is characterised by a deep minimum in the electrical conductivity of about 5 orders of magnitude. A discussion of the Meyer-Neld el and anti-Meyer-Neldel rule fitted to the systems is also included.