High-T_c Superconductivity of van der Waals Condensates

The paper considers the possibility of superconductivity setting in when the distance a_B between molecules (atoms) is such that a_F < a_B < a_W, where a_F and a_W are the equilibrium separations in Fermi metals and van der Waals insulators. The last has no band sructure. This is the binding energy region 40--60 kJ/mol. However, neither stretch of metals ("dilution" by insulators) nor compression of insulators to a=a_B produce substances stable under normal conditions. It was proposed to stabilize such substances prepared of insulators by adsorbing their atoms (molecules) on metal catalysts to obtain (Metal)(Insulator)_X-type systems for X > 1. The well-known method of metal sputtering in a gaseous atmosphere has used to successfully obtain such "sorption compounds" and collect with magnetic funnels clusters of diamagnetic particles kept suspended in a magnetic field gradient ~100 G/cm at 300 K (the levitation effect).