Supercooling of Silicon and Germanium after Laser Melting

Abstract

ABSTRACTFollowing pulsed laser melting, supercoolings of 505 K in Si and 430 K in Ge were observed prior to bulk nucleation. These large supercoolings are obtained because of the extremely high thermal quench which follows laser irradiation. Nucleation rates were estimated to be ∼1029 events/m3/s. Assuming that homogeneous nucleation was achieved, surface energies are estimated to be 0.34 J/m2 for Si and 0.24 J/m2 for Ge. These results are in reasonable agreement with traditional homogeneous nucleation experiments sensitive to rates of only ∼1010 events/m3/s. This laser melting technique is applicable to nucleation studies in a wide variety of materials.