title: A comparison study on Raman scattering properties of alpha- and beta-MnO2.
abstract: In this comment to a recent paper [Anal. Chim. Acta 585 (2007) 241-245], we report a comparison study on Mn oxide-related compounds with different crystallographic forms, which distinguish between beta-MnO(2) and alpha-MnO(2) type materials via Raman scattering (RS) spectroscopy. The tetragonal rutile-type beta-MnO(2) is characterized by a RS band at approximately 667cm(-1) of symmetry A(1g), whereas the alpha-MnO(2) type materials feature two main RS contributions at about 574 and 634cm(-1), belonging to A(g) spectroscopic species of a tetragonal hollandite-type framework. These data represent a clear signature for identifying beta-MnO(2) and alpha-MnO(2) type materials via RS spectroscopy.
authors: Department of Chemistry, Centre for Materials Science and Nanotechnology, University of Oslo, N-0315 Oslo, Norway. tao.gao@kjemi.uio.no
authors: Tao
authors: T
authors: Gao
authors: Helmer
authors: H
authors: Fjellvåg
authors: Poul
authors: P
authors: Norby