CeO2-La0.5Sr0.5CoO3-δ composites for giant permittivity applications

CeO2-La0.5Sr0.5CoO3-delta (LSCO) composites with different LSCO loadings were prepared by the conventional solid-state ceramic route. X-ray diffraction and scanning electron microscopy results show that the composite is a mixture of CeO2 and LSCO. The variation of relative permittivity (measured at 27 degrees C) with sintering temperature shows that the permittivity is maximum when sintered at 1150 degrees C for the volume fraction of 0.4 (epsilon(r) approximate to 10(5)). The permittivity is decreased when sintering temperature increases above 1150 degrees C. For all volume fractions of LSCO, the relative permittivity of CeO2-LSCO composites is almost independent of temperature in the range -30 to 70 degrees C. CeO2-LSCO composites can be a suitable substitute for cermets used in electromechanical and embedded passive devices.