Superconducting organic polymer films

Abstract

A concept of producing superconducting composites by means of reticulate doping of polymers with low molecular weight organic superconductors 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. After annealing at optimized conditions a dramatic change occurs and the composites become metallic in the entire temperature range due to a conversion of various phases of the BEDT‐TTF polyiodides into the metallic and superconducting β1‐phase. The composites show the superconducting transition below 5 K1 as evidenced by magnetoresistance measurements, indicating that the content of the β1‐phase microcrystals in the conducting network exceeds the percolation threshold.