title: Universality in early-stage growth of phase-separating domains near the critical point.
abstract: We present both the experimental and computational methods and results of phase-separating experiments performed with sulfur hexafluoride (SF6) close to its critical density. These experiments were performed in microgravity to suppress buoyancy and convection-driven effects. Phase separation under reduced gravity is analyzed for both 0.3 mK and 3.6 mK temperature quenches in order to derive the early-stage growth law. We found a 1/3 growth law for early stages of phase separation for a volume fraction of minority domains of 50%. Our findings support the hypothesis of a crossover between Brownian motion and hydrodynamic effects in the early stages of phase separation. The temperature inside the bulk of the pure fluid was estimated using a proposed histogram method. Our histogram method allowed temperature estimation below thermistors' sensitivity and detected small temperature variations inside the bulk of the pure fluid.
authors.affiliation: Department of Physics and Astronomy, College of Charleston, 60 George Street, Charleston, South Carolina 29424, USA.
authors.forename: Ana
authors.initials: A
authors.lastname: Oprisan
authors.forename: Sorinel A
authors.initials: SA
authors.lastname: Oprisan
authors.forename: John J
authors.initials: JJ
authors.lastname: Hegseth
authors.forename: Yves
authors.initials: Y
authors.lastname: Garrabos
authors.forename: Carole
authors.initials: C
authors.lastname: Lecoutre-Chabot
authors.forename: Daniel
authors.initials: D
authors.lastname: Beysens