Complex sentence: It was shown in 1976 that oxidation with iodine provides a 10 8-fold increase in conductivity, thus approaching the conductivity of the best available conductor, silver.
Split into simpler sentences: It was shown in 1976 that oxidation of this material with iodine results in a 10 8-fold increase in conductivity. The conductivity of this doped material approache the conductivity of the best available conductor, silver.