Polar lattice vibrations and phase transition dynamics in Pb(Zr.sub.1-x./sub.Ti.sub.x./sub.)O.sub.3./sub..

0368188 - FZÚ 2012 RIV US eng J - Journal Article
Buixaderas, Elena - Nuzhnyy, Dmitry - Petzelt, Jan - Jin, L. - Damjanović, D.
Polar lattice vibrations and phase transition dynamics in Pb(Zr_1-xTi_x)O₃.
Physical Review. B. Roč. 84, č. 18 (2011), 184302/1-184302/12. ISSN 1098-0121
R&D Projects: GA ČR GAP204/10/0616
Institutional research plan: CEZ:AV0Z10100520
Keywords : phonons * lattice dynamics * PZT * IR spectroscopy
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 3.691, year: 2011

Infrared (IR) reflectivity spectra of nominally pure Pb(Zr1-xTix)O3 ceramics with different Ti/Zr concentration (x = 0.42 – 0.58) were measured and evaluated along with the time-domain THz transmittance spectra in the temperature range 10 – 900 K. The temperature dependence of the low-frequency vibrations, related to Pb atoms, was analyzed in terms of two overdamped modes –a soft mode and an anharmonic hopping central mode– in the cubic and high-temperature ferroelectric phase, and three main vibrations in the low-temperature ferroelectric phase with the doubled unit cell: two E-symmetry modes (the soft mode and a mode corresponding to anti-phase vibrations of neighbouring Pb atoms in the THz range), and the antiferrodistortive mode producing the anti-phase tilts of the oxygen octahedra. The last bare mode is not IR active, but it becomes activated by coupling with the soft mode.
Permanent Link: http://hdl.handle.net/11104/0202599