Effect of restricted geometry on superconducting properties of low-melting metals

This contribution is a review of results obtained at studies of influence of artificially restricted geometry conditions on superconducting properties of nanoparticles of low-melting metals (Hg, Pb, Sn, In). The restricted geometry conditions have been achieved at embedding of melted metals under high pressure into two types of nanoporous matrices: channel structures on base of chrysotile asbestos and porous alkali-borosilicate glasses. The chrysotile asbestos is a system of parallel nanotubes with the channel diameter from 2 up to 20 nm and with an aspect ratio (length/channel diameter) up to ∼ 107. The porous glasses have a random dendrite interconnected 3D net of channels (pores) with technologically regulated average pore diameter from 3 up to 30 nm. The temperature dependences of resistance and heat capacity in a vicinity of superconducting transition and the dependencies of critical temperatures vs. average pore diameters are presented. The values of critical magnetic fields are determined. © E.E. Zubov, 2016.