Coherence-length effects on the nucleation of superfluid transitions in liquid-helium mixtures

Abstract
A theory of the nucleation of superfluid transitions near container walls of He3-He4 mixtures is developed. The theory uses a local-continuum model, which accounts for wall-potential-induced concentration and pressure gradients, supplemented by an important coherence-length correction to account for the finite thickness of the nucleation films. An excellent one-parameter fit to the available experimental data is obtained. The theory provides support for the concept of universality in phase-transition phenomena.