Dielectric loss of half-doped manganite La0.5Ca0.5MnO3

Abstract

The dielectric loss tanδ of half-doped manganite La0.5Ca0.5MnO3 is investigated using Green's function technique. The La0.5Ca0.5MnO3 is described by the Kondo-lattice model in the double exchange limit, taking into account the Jahn—Teller distortion and the super-exchange interaction between the localized electrons. It is found that the intensity of tanδ decreases with increasing |εJT|, V, and U. It is also observed that the transition temperature TP rises as |εJT| and U increase. It is worth noting that TP remains unchanged and the strength of tanδ increases with increasing g. The calculated dielectric loss results are explained theoretically, and these behaviors are in qualitative agreement with the experimental results.