Anomalous strong repulsive step-step interaction on slightly misoriented Si(113)

We have used scanning tunneling microscopy to study Si(113) 0.2 degrees misoriented towards [1(1) over bar0$]. Rapid quenching of this surface from 1500-1575 K to room temperature results in a uniformly stepped single-domain surface, whereas slower cooling gives rise to clustering of steps. The thermally induced step wandering and the terrace width distribution of the uniformly stepped surface are analyzed in order to determine the strength of the energetic and entropic step-step interactions. Beside the short-range attractive step-step interaction found by Song and Mochrie [Phys. Rev. Lett. 73, 995 (1994)] on Si(113) misoriented 1 degrees-5 degrees towards [001], we found an anomalously strong long-range repulsive step-step interaction on Si(113) 0.2 degrees misoriented towards [1(1) over bar0$]. The coexistence of a long-range repulsive and a short-range attractive step-step interaction may explain the transition from a uniformly stepped surface at high freeze in temperature to a faceted surface at lower freeze in temperatures.