Phonon modes and local polar distortions in nanoclusters of Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 crystals probed by terahertz reflectance spectra and Raman scattering. (20th April 2015)

• Record Type: Journal Article
• Authors: Zhu, J J; Zhang, J Z; Xu, G S; Zhang, X L; Hu, Z G; Chu, J H
• Is Part Of: Laser physics letters. Volume 12:Number 5(2015:May)
• Publication Date: 2015-04-20
• Subjects: ferroelectric -- terahertz reflectance spectra -- Raman scattering -- crystal -- morphotropic phase boundary -- soft mode; Lasers -- Periodicals; Physics -- Periodicals; 621.366
• DOI: 10.1088/1612-2011/12/5/056103
• Languages: English
• ISSNs: 1612-2011

Abstract

Abstract: Optic phonons and lattice vibrations of Pb(In1/2 Nb1/2 )O3 -Pb(Mg1/3 Nb2/3 )O3 -PbTiO3 single crystals near the morphotropic phase boundary (MPB) are determined by terahertz (THz) reflectance spectra in a temperature range of 5.5–300 K. Raman scattering is measured with a He–Ne laser with a wavelength of 632.8 nm as the exciting source. On cooling from 300 K, the A 1 component of the splitting TO1 mode hardens, which follows the Cochran law with a critical softening temperature of 761–861 K. Moreover, the E component of the soft mode is heavily damped around 0.81 THz (27 cm − 1 ). Additional polar phonon modes, which are forbidden in the cubic structure, are activated due to the broken cubic symmetry in polar clusters.