In Sect.2.3 we have discussed the Landau domain theory which gives a reasonable description of the dimensions of the normal and superconducting domains in the intermediate state of type-I superconductors. According to the result of Landau’s nonbranching model, indicated in (2.40), with decreasing sample thickness the domain width of the intermediate-state structure decreases and the (positive) wall energy contributes more and more to the free energy of the superconductor. Because of this, the critical field perpendicular to a planar superconducting film decreases with decreasing film thickness and would become zero when the film thickness is about equal to the wall energy parameter δ [2.3]. TINKHAM [5.1] was the first to point out that films of type-I superconductors with a thickness less than the coherence length assume an Abrikosov vortex state in a perpendicular magnetic field, similar to the mixed state in type-II superconductors.
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- 5.5G.J. Dolan, J. Silcox: Proc. Intern. Conf. Low Temp. Phys. LT 13, 1972, Vol. 3, ed. by K.D. Timmerhaus, W.J. O’Sullivan, E.F. Hammel (Plenum Press, New York 1974) p.147Google Scholar
- 5.9E. Guyon, C. Caroli, A. Martinet: J. Phys. Radium 25, 683 (1964)Google Scholar
- 5.10J. Pearl: Low Temperature Physics — Lt 9, ed. by J.G. Daunt, D.V. Edwards, F.J. Milford, M. Yaqub (Plenum Press, New York 1965) part B, p.566Google Scholar