Significant electroresistance effect tuned by oxygen stoichiometry in La0.5Ca0.5MnOz

We report the electroresistance (ER) effect tuned by oxygen stoichiometry in La0.5Ca0.5MnOz. ER value varies from positive to negative, and is enhanced with the absolute maximum approaching a percentage of several thousands with lowering of the oxygen content, and the underlying physical mechanism of ER effect varies with the oxygen stoichiometry. We give a reasonable explanation on the mechanism of ER effect for the self-doped La0.5Ca0.5MnOz. In addition, the observation of the ER effect tuned by oxygen content may open up new routes to potential applications.