The anharmonic one-particle potential (OPP) parameters of rutile (TiO2) have been directly determined by least-squares refinement of the nuclear-density distribution, which is obtained by the maximum-entropy method (MEM) analysis using neutron powder-diffraction data. In order to construct an appropriate OPP model, the mean-square displacements of the MEM nuclear density are calculated and compared with that of OPP. From this comparison, it is concluded that the effective orders of OPP are fourth for the Ti atom and third for the O atom, respectively. Six fourth-order and three third-order anharmonic parameters were determined for the Ti and O atoms. No correlation problems between parameters were encountered in the analysis.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering