Magnetization and size effect of hard superconductors

Abstract

For cylindrical samples of hard superconductors formulae basing upon the theory of Irie and Yamafuji are deduced and used for a calculation of the irreversible portion of magnetization. It is possible to represent the irreversible magnetization in a simple reduced form. The values of maximum magnetization of specimens of a Nb‐64 at% Ti alloy with different thickness and annealing fit to the straight line ‐4 π M̄max = 0.458 Hmax + 31.6. Hc1 = 58 Oe and the reversible magnetization curve of this alloy were determined. By these the irreversible portion of experimental magnetization curves is determined and compared with the calculations. The causes of deviations are discussed.