Fullerenes: Thermomechanics, Doping, Electrical Conductivity

Overview

Fullerenes, the allotropic variety of carbon, have many interesting thermophysical properties. Their behaviors during thermodynamical processes are very sensitive on doping by foreign atoms. The position of an impurity in the fullerene cage decides which electrical conductivity phase (conducting, semiconducting, superconducting) it is in. Fullerenes are also able to form a molecular crystal. There are three possibilities to implant impurities into a fullerene structure. The first one concerns addition of an alkali or rare earth metal ion into interior of the cage. The next is based on the substitutional doping of an impurity atom in a different valence state that replaces a carbon atom on the surface of the fullerene cage. The last method concerns implanting a foreign atom into the interstitial position of the fullerene molecular crystal. States of that allotropic variety of carbon depend strongly on many external influences like temperature, heat flux, concentration, mass...