Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

First Principles Calculations of Clean, Oxidized, and Reduced beta-MnO2 Surfaces

Published

Author(s)

Gloria A. Oxford, Anne M. Chaka

Abstract

Stoichiometric and defective terminations of the β-MnO2 (110), (100), and (101) surfaces are investigated as a function of oxygen partial pressure and temperature using ab initio thermodynamics. In agreement with studies on other rutile-type minerals, the (110) surface is predicted to be the most stable surface, followed by the (100) surface and then the (101) surface. The (110) and (101) surfaces are found to oxidize by formation of stable manganyl groups (Mn=O) at high oxygen chemical potentials, whereas the (100) surface is not likely to be oxidized under experimentally relevant conditions. All of the β-MnO2 surfaces studied undergo reduction processes in UHV, resulting in many complicated structural changes. A number of the reduced surfaces exhibit new surface reconstructions not yet observed for any rutile-type mineral. Analysis of the dependence of manganese coordination geometry on oxidation state is carried out to facilitate understanding of the surface reconstructions. It is determined that the competition between optimizing d-orbital occupation and minimizing steric and repulsive electrostatic interactions drives the surface reconstructions observed for reduced β-MnO2 surfaces. Symmetry-breaking at the surface allows for Jahn-Teller distortion of the reduced MnIII coordination sphere for some surface reconstructions.
Citation
Journal of Physical Chemistry C
Volume
115
Issue
34

Keywords

ab initio thermodynamics, density functional theory, manganese dioxide, molecular orbital analysis, surfaces

Citation

Oxford, G. and Chaka, A. (2011), First Principles Calculations of Clean, Oxidized, and Reduced beta-MnO2 Surfaces, Journal of Physical Chemistry C, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=907825 (Accessed May 20, 2024)

Issues

If you have any questions about this publication or are having problems accessing it, please contact reflib@nist.gov.

Created September 1, 2011, Updated January 27, 2020