Mobility of lithium ions in the crystal structure of lithium gadolinium molybdate LiGd(MoO4)2

Dielectric spectroscopy was used to show that, for LiGd(MoO4)2, a complex molybdate with a stoichiometric oxygen content and a scheelite-type structure, the electric conduction in a wide temperature range mainly occurs via Li+ ions. The dielectric relaxation in a c-axis-cut single crystal was studied over the temperature range 400-1000 K within the framework of the model of thermal ion jumps. This model yielded a minimum jump length for Li+ ions of 1.32 Å and a height of the potential barrier between the nearest positions of ions of 1.65 eV, a value close to the conduction activation energy below the melting point of the crystal.