Low temperature dielectric properties of Ce0.8Gd0.2O1.9 films

► Low T dielectric properties of Ce0.8Gd0.2O1.9 films with/out substrate were measured. ► The grain boundary conductivity of both types of films freezes out below 150 K. ► Below 150 K, the effective dielectric constant of both types of films is 20.5±2.5. ► The dielectric constant of self-supported films is weakly unstable between 80-140 K. ► Defect ordering may cause the unstable dielectric constant of self-supported films.