Topics in transport phenomena near the critical point

The mode-mode coupling theory of Kadanoff and Swift for the estimation of, transport coefficients near the critical point is applied to the calculation of the electrical conductivity near the superconducting transition and to the calculation of the attenuation coefficient for longitudinal sound waves near the magnetic transition. The rise in the electrical conductivity as a material approaches its superconducting transition is described. Near T c small regions become superconducting and can carry an anomalous current, thereby causing a rise in conductivity. The use of the Kubo formula permits the estimation of the contribution from this source. A comparison of this estimate with previous theories and experiment is carried out. The rise in the ultrasonic attenuation as a material approaches its magnetic transition is described. Near the transition small regions become magnetically ordered and their interaction with the sound wave is enhanced, thereby causing increased absorption of the sound. The Kadanoff and, Swift formalism permits the estimation of this increased attenuation. Predictions are made of the increased attenuation in various models of magnetic systems. A comparison with experiment is carried out.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Year dc:date

2011

Author dc:creator

• Laramore, George Ernest

Contributors dc:contributor

• Kadanoff, L.P.

• transport phenomena
• mode-mode coupling theory
• transport coefficients near the critical point
• superconducting transition

Statement dc:rights

• 1969 George Ernest Laramore

Language dc:language

en

Identifier

6075480

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/25786