Temperature dependent reflection electron diffraction study of In(1 1 1) and observation of laser-induced transient surface superheating

The high temperature behavior of the In(1 1 1) surface is investigated using reflection high-energy electron diffraction. The In(1 1 1) surface remains ordered when heated at a slow rate up to the highest temperature studied, 4 K below the bulk melting point. The surface vacancy density is observed to increase with temperature; however, the average random step terrace width remains unchanged from its value at room temperature. Transient surface superheating of the In(1 1 1) surface by 73±9 K above its bulk melting point is observed using 100-ps laser pulsed heating, which provides a heating rate of ∼1012 K s−1. The dependence of the diffraction intensity on temperature gives a surface Debye temperature of 49±10 K. The possibility of surface annealing after laser superheating and melting is also investigated, but no annealing is observed.