Electroresistance effect in La1−xCaxMnO3 (0<x<1) ceramics

Electroresistance (ER) effects were investigated for a full series of manganite ceramics La_1−xCa_xMnO₃ (0<x<1), synthesized by solid state reaction. The results indicate that while the ER effects are large only in the presence of electrically active, high E-field boundaries, the equilibrium or metastable electronic-magnetic states in the adjoining domains are also significant, as a large ER occurs only at x=0.51 and x=0.17; those compositions are both near a two-phase coexistence region, i.e. close to a compositional regime where equilibrium insulating/metallic phase domains and interfaces would occur spontaneously.