Researchers at Tokai University have created materials obtained by bringing n-alkanes into contact with graphite which are capable of conducting electricity with almost no energy loss at room temperature. They report that the sudden jump in resistance showing a phase transition is observed in the materials during heating by two-probe resistance measurement. The measured critical temperatures of the materials consisting of pitch-based graphite fibers and n-alkanes having 7-16 carbon atoms range from 363.08 to 504.24 K (231 Celsius) and the transition widths range between 0.15 and 3.01 K. They also demonstrate that superconductors with critical temperatures beyond 504 K (231 Celsius) are obtained by alkanes with 16 or more carbon atoms.
In 1986, a cuprate superconductor (Ba-La-Cu-O system) having a critical temperature which goes over the BCS limit (~30 K) was discovered and then a cuprate superconductor (Y-Ba-Cu-O system) with a critical temperature higher than 77 K was discovered. Furthermore, a Hg-based cuprate with a critical temperature of 133 K was found. The 133 K is still the highest critical temperature of conventional superconductors under atmospheric pressure