Magnetic-field-dependent dielectric constant in La2/3Ca1/3MnO3

We report a rather high dependence of the dielectric permittivity on the magnetic field in La2∕3Ca1∕3MnO3. The variation is maximum at around 270K, little above the Curie temperature TC, and it reaches a 35% under only 0.5T. We attribute this phenomenon to the space-charge or interfacial polarization produced between the insulator and the metallic regions segregated intrinsically in the material above TC.