the diameter of carbon peapods range from ca. 1 to 50 nanometers. various combinations of fullerene c sizes and nanotube structures can lead to various electric conductivity property of carbon peapods due to orientation of rotations. for example, the c @ (10,10) is a good superconductor and the c @ (17,0) peapod is a semiconductor. the calculated band gap of c @ (17,0) equals 0.1 ev. research into their potential as semiconductors is still ongoing. although both the doped fullerides and ropes of swnts are superconductors, unfortunately, the critical temperatures for the superconducting phase transition in these materials are low. there are hopes that carbon nano-peapods could be superconducting at room temperature.