Novel nanocrystalline mixed conductors based on LiFeBO3 glass

Novel nanocrystalline mixed conductors were obtained by thermal nanocrystallisation of lithium-iron-borate glasses (nominally LiFeBO3) prepared via melt-quenching method. After heat treatment, a glass-ceramics consisting of FeBO3 and LiFeBO3 phases was obtained. Grain sizes, estimated using Scherrer formula, were 45-50 nm and 70-80 nm, respectively. Value of electrical conductivity of the initial glass was estimated as 5.8·10−12 S cm−1. After annealing at 475 °C, a growth by a factor 2.4·106 was observed, leading to final conductivity value  1.4·10-5S cm−1 at room temperature. The activation energy of electronic conductivity was lowered from 0.81 eV for glass to 0.18 eV for thermally treated material.