title: Surface vibrational modes of alpha-quartz(0001) probed by sum-frequency spectroscopy.
abstract: Infrared-visible sum-frequency spectroscopy was used to probe surface vibrations of alpha-quartz(0001) under ambient conditions. Two modes at 880 and 980 cm(-1) were observed and identified as arising from Si-O-Si and Si-OH structures of the surface. Heat treatment and hydroxylation could convert Si-OH to Si-O-Si and vice versa. The technique is generally applicable to studies of surface phonons of other oxides, semiconductors, and insulators.
authors.affiliation: Physics Department, University of California at Berkeley, Berkeley, California 94720, USA.
authors.forename: Wei-Tao
authors.initials: WT
authors.lastname: Liu
authors.forename: Y R
authors.initials: YR
authors.lastname: Shen