Anisotropy effects in the critical field of superconducting tin-indium alloys

Measurements have been made of the critical-field curve, Hc versus T, for eight superconducting dilute alloys of indium in tin near the critical temperature and at low temperatures extending to about 0.30 K. The effective magnitude of the superconducting energy gap is sensitive to the direction of the electron momentum relative to the crystal lattice - the so-called anisotropy effect. The reduction in electron mean free path which occurs upon addition of indium to pure tin reduces the effect of anisotropy in the electron-electron interaction. The decrease in the effect of anisotropy has been observed to depress the critical temperature Tc, the 0oK critical field Ho and the constant K = 2nyTc2/(VH2). In terms of the reduced critical-field curve, impurity additions are found to reduce the deviation from the parabolic law, h = 1 - t2. The observations are explained by theoretical predictions of Clem for which the meansquared anisotropy in pure tin is taken to be (a2) = .014 ± .001.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Year dc:date

2011

Author dc:creator

• Montgomery, David Carey

Contributors dc:contributor

• Mapother, D.E.

• anisotropy effects
• critical field
• superconducting tin-indium alloys
• crystal lattice

Statement dc:rights

• 1967 David Carey Montgomery

Language dc:language

en

Identifier

6105147

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/25721