The geometrical structure of the (310) surface was investigated by using high-resolution low-energy electron diffraction. An ideally truncated (310) surface exhibited a staircase geometry in which each unit consisted of a (100) terrace, 3 row-spacings wide, separated by a single-height step. However, it was found that the surface was reconstructed, with both the terrace width and the step height tripled on average, while the surface retained the (310) orientation. In addition, a small number of double-height steps was found to coexist with the triple-height steps.

J.K.Zuo, D.M.Zehner: Physical Review B, 1992, 46[24], 16122-7