Thermophysical and Microwave Shielding Properties of La0.5Sr0.5CoO3-δ and its Composite with Epoxy

The microwave shielding properties of the perovskite oxide conductors, La0.5Sr0.5CoO3-delta (LSCO), were investigated. The sintered LSCO sheets were showing excellent microwave shielding properties up to 35-42 dB in the entire X and Ku bands. Towards getting a light-weight and easily processable structure, an attempt was made to composite LSCO with the easily mouldable polymer, epoxy. The thermal, dielectric and electromagnetic wave shielding properties of the composites were studied. The mechanical strength, thermal expansivity and thermal conductivity of the composites were progressively improved with LSCO addition. An improvement in the shielding effectiveness was observed with filler addition and attained a value of 10 dB in the range of 8.2-10 GHz for a maximum loaded LSCO-epoxy composite and the value spans from 3 dB to 9 dB in the Ku band region. The improvement in the shielding effectiveness with filler addition was supplemented by the gradual improvement in the dielectric permittivity, dielectric loss and AC conductivity.