EPR observation of the spin pair correlation above Tc in lightly alkali metal-doped C60 fullerene Original Research Article

The existence of two temperatures: Tp-Cooper pairing and Tc-Bose–Einstein condensation in high temperature superconductors has been stipulated in a lightly potassium-doped C60 by Magnetically Modulated Microwave Absorption. This doping level corresponds to the carrier density greater than the critical one: x>x1. In case of rubidium lightly doped C60, where the carrier density x was smaller than the critical one: x