A study of the surface reconstruction of Y(11▪0) revealed a 6-fold symmetrical low-energy electron diffraction pattern instead of the 12-fold symmetrical pattern which had previously been reported. This indicated that only one orientation of close-packed atoms existed on the surface. Collapse of the surface unit cell was uniaxial, and occurred along the [00▪1] direction. This produced the same commensurate surface structure as that found previously for the (11▪0) (7 x 1) reconstructions of Ho and Er. It was suggested that this structure was influenced by the presence of surface defects; thus inducing collapse of the unit cell along the [10▪0] direction to form an incommensurate domain with an approximately equal probability to that of the commensurate (7 x 1) domain.

S.D.Barrett, R.I.R.Blyth, S.S.Dhesi, K.Newstead: Journal of Physics - Condensed Matter, 1991, 3[12], 1953-6