Interrelation of electrical, superconducting, and structural characteristics of low-temperature indium thin films
Abstract
A comprehensive study was made of the electrical, superconducting, and structural properties of indium thin films obtained by condensation on a substrate cooled with liquid helium. Structural electron diffraction analysis made it possible to refine the general law governing the annealing processes occurring when the cold-deposited films are warmed up. The annealing of indium films to about 80–100°K is found to entail an irreversible growth of the interplanar separations owing to a reduction of the inhomogeneous microstresses. When the films are warmed from 100 to 300 °K the main annealing processes are determined by the growth of crystallites and the appearance of a predominant orientation in them. The variation of the residual resistance and of Tc as the cold-deposited films are warmed is explained on the basis of the structural data obtained. In particular, a direct relation is established between the crystallite size and the value of Tc.