Reconstructive phase transitions on (331) were investigated by using scanning tunnelling microscopic and reflection high-energy electron diffraction techniques. It was found that the (12 x 1) to (1 x 1) phase transition comprised 2 stages. In the lower-temperature stage, the domain size of the reconstruction decreased as the temperature increased. This stage involved domain boundary proliferation, and was a continuous phase transition. In the higher-temperature stage, the reconstructed (331) facets disappeared. This stage was a first-order phase transition.

H.Hibino, T.Ogino: Physical Review B, 1996, 53[23], 15682-7