Evidence for Pb-O Covalency in Tetragonal PbTiO 3
Year: 2001
Type: article
Abstract: Accurate charge-density distributions of cubic and tetragonal ${\mathrm{PbTiO}}_{3}$ and ${\mathrm{BaTiO}}_{3}$ have been obtained by the MEM(maximum entropy method)/Rietveld analysis using synchrotron-radiation powder data. The Pb-O bonds in tetragonal ${\mathrm{PbTiO}}_{3}$ show rather strong covalency, while those in cubic ${\mathrm{PbTiO}}_{3}$ are ionic. This is the clear evidence of the Pb-O hybridization in tetragonal ${\mathrm{PbTiO}}_{3}$, which has been theoretically predicted as a key factor of much larger ferroelectricity of this substance than that of ${\mathrm{BaTiO}}_{3}$. Tetragonal ${\mathrm{PbTiO}}_{3}$ forms a layered structure of a two-dimensional covalent-bonding network consisting of the $\mathrm{Ti}\ensuremath{-}{O}_{5}$ pyramid.
Source: Physical Review Letters
Institutions: Okayama University, Rigaku (Japan), Nagoya University
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1982309691