Equilibrium Shapes of Small Lead Crystals: Observation of Pokrovsky-Talapov Critical Behavior

Abstract

Equilibrium crystals of Pb in the temperature range 200- 300\ifmmode^\circ\else\textdegree\fi{}C exhibit facets and curved surfaces which are joined at "smooth" edges (no slope discontinuity). Recent theoretical interpretation has suggested that the crystal shape near such edges should show interfacial critical anomalies. Observation via scanning electron microscopy of 2-10-\ensuremath{\mu}m Pb crystals reveals a critical exponent which is consistent with theoretical identification as belonging to the Pokrovsky-Talapov universality class.