2-STAGE PHASE-TRANSITION OF 12X1 RECONSTRUCTION ON SI(331)

Reconstructive phase transition on Si(331) has been investigated using scanning tunneling microscopy and reflection high-energy electron dif fraction. The (12x1)-to-(1x1) phase transition consists of two stages. In the lower-temperature stage, the domain size of the reconstruction decreases as the temperature increases. This stage is the process of domain boundary proliferation and is a continuous phase transition. In the higher-temperature stage, the reconstructed (331) facets disappea r, and this stage is a first-order phase transition.