Theoretical modeling of infrared spectra of twinned lead zirconate

0481422 - FZÚ 2018 RIV GB eng J - Journal Article
Dočekalová, Zuzana - Pasciak, Marek - Hlinka, Jiří
Theoretical modeling of infrared spectra of twinned lead zirconate.
Phase Transitions. Roč. 90, č. 1 (2017), s. 17-23. ISSN 0141-1594. E-ISSN 1029-0338
R&D Projects: GA ČR GA15-04121S
Institutional support: RVO:68378271
Keywords : domains * IR spectroscopy * dielectric permittivity * lead zirconate * shell model * Born effective charge
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 1.028, year: 2017

The THz-frequency range dispersion of the complex dielectric permittivity tensor of antiferroelectric lead zirconate, associated with its multiple weak infrared active phonon modes, is modelled by the oscillator formula with parameters fully determined from the recently developed atomistic shell model. The resulting realistic dielectric function is used to estimate the far-infrared reflectivity spectra of a twinned lead zirconate crystal in the limit of narrow and wide domains. It is shown that in case of the sufficiently narrow domain widths, the effective-medium average permittivity shows additional modes identified as geometric resonances (i.e. extraneous excitations created by material interfaces), possibly distinguishable in suitable experiments.

Permanent Link: http://hdl.handle.net/11104/0276990