Alkali metal doping effect in conducting polymer-C60 composites: low-field microwave absorption and susceptibility study

Superconducting phases in composites of C60 with various types of conducting polymer (CP) doped by alkali metals are studied by LFMA and susceptibility measurements. LFMA signal drastically changes due to the metallization of CP with increasing alkali metal doping level. At large C60 content, Paramagnetic Meissner Effect is confirmed in field cooling curve. The existence of intergranular and intragranular junctions is supported from the results of AC susceptibility measurements.