The crystallization phenomenon on a modified phosphate glass interpreted through the correlation between the a.c. electrical behaviour and the non isothermal nucleation

Highlights: • Lithium phosphate glass to a vitro-ceramic by homogeneous nucleation. • Structural changes detection using impedance spectroscopy correlated to DSC scan. • Polarization behaviour as evidence of the crystalline structures birth in a glassy matrix. • Devitrification phenomenon using a Gaussian approximation with the elements of M. Avrami's theory. The electrical behavior of a bismuth-phosphate glass lithium ion conductor is studied in a very wide temperature range, from 39 K to 843 K, encompassing the glassy state, passing through the glass transition temperature, and reaching devitrification. The relationship between the structural changes caused by the thermal treatment and the resulting electrical response is interpreted through the dc conductivity and ac permittivity. An isothermal and a non-isothermal treatment allows to propose a simple analysis of the energy distribution and atoms rearrangement times involved in devitrification, using a Gaussian approximation method considering the fundamental elements in the M. Avrami's generalized theory.