# Critical Casimir effect in three-dimensional Ising systems: Measurements on binary wetting films

## Overview

**Authors:** Masafumi Fukuto, Yohko F. Yano & Peter S. Pershan

**Source:** Physical Review Letters, Vol.94, 135702, (2005)

**Soft Matter key words:** thermodynamic Casimir force, correlation length, thin films, wetting

## Abstract

I analogy to the quantum electrodynamics casimir force, arising between conducting plates due to confinement of zero-point fluctuations of vacuum fields, a thermodynamics Casimir force has been introduced. The latter arises by confining a fluid with diverging bulk correlation lenght <math>\ksi</math> to a finite dimension L. Authors of this paper set out to experimentally confirm theoretical predictions for this force, in binary thin wetting films close to liquid/vapor coexistence. They extract a Casimir amplitude <math>\Delta_{+-}</math> as well as a Casimir scaling function <math>\theta_{+-}</math> which, they find, depends monotonically on dimensionality.