Dielectric properties in LaFe0.5Ga0.5O3

In order to study the electronic conduction in LaFe0.5Ga0.5O3, dielectric properties have been mainly investigated below TN≃215K along with dc measurements, where TN is the Néel temperature which was obtained by magnetic measurement. In dielectric loss factor, a relaxation process with a hopping energy of 0.32 eV shows up. Such a process is an evidence for polaronic conduction of adiabatic small polarons taking place in bulks as well as LaFeO3. The reduction of the hopping energy due to Ga-doping has been discussed based upon the polaron theory. It has been found out that variations of optical dielectric constant and polaron radius by Ga-doping are mainly responsible for the small hopping energy in LaFe0.5Ga0.5O3.