SUPERCONDUCTING ORGANIC POLYMER-FILMS

A concept of producing superconducting composites. by means of reticul ate doping of polymers with low molecular weight organic superconducto rs is presented. The obtained polycarbonate films contain around 2 wt. % of BEDT-TTF polyiodides in a form of continuous crystalline network. D.c. and microwave conductivity measurements demonstrate, that the as -obtained reticulate composites show semiconducting-type properties. A fter annealing at optimized conditions a dramatic change occurs and th e composites become metallic in the entire temperature range due to a conversion of various phases of the BEDT-TTF polyiodides into the meta llic and superconducting beta(t)-phase. The composites show the superc onducting transition below 5 K, as evidenced by magnetoresistance meas urements, indicating that the content of the beta(t)-phase microcrysta ls in the conducting network exceeds the percolation threshold.