Electrostriction of Near-Critical SF6 in Microgravity

摘要

We used interferometry to measure the electric-field-induced (i.e., 'electrostrictive') increase of the density of sulfur hexafluoride near its critical point. The results at the temperatures T(sub c) + 5 mK, T(sub c) + 10 mK, and T(sub c) + 30 mK with T(sub c) = 319 K agree with a calculation based on the Clausius-Mossotti relation and the restricted cubic model equation of state. These measurements were performed in microgravity so that the electrostrictive density changes (less than or equal to 3.5% in this work) would not be complicated by stratification of the fluid's density induced by the Earth's gravity.