--- res: bibo_abstract: - The existence of localized vibrational modes both at the positive and at the negative LiNbO3 (0001) surface is demonstrated by means of first-principles calculations and Raman spectroscopy measurements. First, the phonon modes of the crystal bulk and of the (0001) surface are calculated within the density functional theory. In a second step, the Raman spectra of LiNbO3 bulk and of the two surfaces are measured. The phonon modes localized at the two surfaces are found to be substantially different, and are also found to differ from the bulk modes. The calculated and measured frequencies are in agreement within the error of the method. Raman spectroscopy is shown to be sensitive to differences between bulk and surface and between positive and negative surface. It represents therefore an alternative method to determine the surface polarity, which does not exploit the pyroelectric or piezoelectric properties of the material.@eng bibo_authorlist: - foaf_Person: foaf_givenName: S. foaf_name: Sanna, S. foaf_surname: Sanna - foaf_Person: foaf_givenName: Gerhard foaf_name: Berth, Gerhard foaf_surname: Berth foaf_workInfoHomepage: http://www.librecat.org/personId=53 - foaf_Person: foaf_givenName: W. foaf_name: Hahn, W. foaf_surname: Hahn - foaf_Person: foaf_givenName: A. foaf_name: Widhalm, A. foaf_surname: Widhalm - foaf_Person: foaf_givenName: Artur foaf_name: Zrenner, Artur foaf_surname: Zrenner foaf_workInfoHomepage: http://www.librecat.org/personId=606 orcid: 0000-0002-5190-0944 - foaf_Person: foaf_givenName: W. G. foaf_name: Schmidt, W. G. foaf_surname: Schmidt bibo_doi: 10.1109/tuffc.2011.2012 bibo_issue: '9' bibo_volume: 58 dct_date: 2011^xs_gYear dct_isPartOf: - http://id.crossref.org/issn/0885-3010 dct_language: eng dct_publisher: Institute of Electrical and Electronics Engineers (IEEE)@ dct_title: Vibrational properties of the LiNbO3 z-surfaces@ ...