MICROWAVE PROPERTIES OF INHOMOGENEOUS YBA2CU3O7

Microwave properties of the powder specimen of high-T(c) superconductor YBa2Cu3O7 were examined with the standing-wave method at 9.12 GHz. From the analysis based on the coexistence of superconductivity and dielectricity, the phenomenological penetration depth is found to be as large as 0.3 cm in the power specimen. The temperature dependence of the penetration depth in the power specimen resembles that of London penetration depth in the compact material. The imaginary part of the dielectric permittivity diverges at the superconducting phase transition, the origin of which can be attributed to either fluctuations or the Josephson effect.