title: Electric field gradient effects in raman spectroscopy.
abstract: Raman spectra of materials subject to strong electric field gradients, such as those present near a metal surface, can show significantly altered selection rules. We describe a new mechanism by which the field gradients can produce Raman-like lines. We develop a theoretical model for this "gradient-field Raman" effect, discuss selection rules, and compare to other mechanisms that produce Raman-like lines in the presence of strong field gradients. The mechanism can explain the origin and intensity of some Raman modes observed in SERS and through a near-field optical microscope (NSOM-Raman).
authors.affiliation: Physics Department, North Carolina State University, Raleigh, North Carolina 27695-8202, USA.
authors.forename: E J
authors.initials: EJ
authors.lastname: Ayars
authors.forename: H D
authors.initials: HD
authors.lastname: Hallen
authors.forename: C L
authors.initials: CL
authors.lastname: Jahncke