The structure and polarization of the as-yet hypothetical Ruddlesden-Popper compound Pb 2TiO 4 are investigated within density-functional theory. Zone center phonons of the high-symmetry K 2NiF 4-type reference structure, space group I4/mmm, were calculated. At the theoretical ground-state lattice constants, there is one unstable infrared-active phonon. This phonon freezes in to give the I2mm ferroelectric state. As a function of epitaxial strain, two additional ferroelectric phases are found, with space groups I4mm and F2mm at compressive and tensile strains, respectively.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Mar 1 2005|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics