Abstract
Supercooled p-cresol melt was investigated using polarized light scattering method under low-gravity. Relaxation of metastable liquid was induced by applying pressure change within the range of 1- 160 bar. Convective flow was observed after changing pressure, showing inhomogeneous density change in the sample. Remarkable oscillation of scattering intensity was observed under gravity, whereas low-gravity experiments showed single peak after changing pressure. These results indicates convective flow affects the processes of pressure relaxation in supercooled melts. In applying Landau's phenomenological theory of phase change, macroscopic flow was related to the molecular ordering. Correlation length of ordered clusters under low-gravity was estimated to be 2.3 times larger than that of clusters under gravity. Thus convective shear flow diminished the size of clusters against the ordering tendency due to non-equilibrium conditions. Both forces are considered to induce the observed oscillatory relaxation under gravity.
