Separation of grain boundary effects and intrinsic properties in perovskite-like Gd0.6Y0.4BaCo2O5.5 using high-frequency dielectric spectroscopy -: art. no. 184403

The dielectric response of Gd0.6Y0.4BaCo2O5.5, which undergoes a sequence of magnetic and electronic phase transitions, has been investigated in the radio-frequency range from 1 MHz to 1.8 GHz in order to separate the intrinsic properties from grain boundary and sample-electrode interface effects. Analysis of the measured response, showing the characteristics of a damped resonator, reveals the intrinsic dc resistivity, which cannot be detected using the standard four-point measurement method. From the skin-effect-governed dielectric response the temperature dependence of the magnetic permeability was determined.