The effect of steps upon the structural phase transition of the (111)-(7 x 7) structure dimer-adatom-stacking fault structure was investigated by using a cell model. This model described the state of the (111) surface in units of 7 x 7 triangular halves. The presence of steps was expected to suppress hysteresis. Calculations of the temperature dependence of the order parameter were performed by using a Monte Carlo simulation in the presence of steps. Upon assuming reasonable values for the formation energy of the dimer-adatom-stacking fault cell, at the step edges and the intervals between the steps, the calculated results agreed with experimental data with regard to hysteresis.

Effect of Steps on Structural Phase Transitions of Si(111)-(7 x 7) Surfaces. T.Kato, T.Takajyo, H.Tochihara, W.Shimada: Japanese Journal of Applied Physics - 1, 2000, 39[7B], 4307-10