Terahertz Response of Ferroelectric Nanofibers

by Tian, Zhen; Xin, Kun; Wang, Mingwei; Han, Jiaguang; Wang, Haizhen; Tian, Z. Ryan; Zhang, Weili

Far-infrared optical and dielectric properties of ferroelectric SrTiO(3) and BaTiO(3) nanofibers, prepared by hydrothermal syntheses, were studied using terahertz time-domain spectroscopy. The power absorption, refractive index, and complex dielectric function were characterized in the frequency range from 0.2 to 1.0 THz. The measured results are well reproduced by theoretical fittings based on the dielectric models and the effective medium model. The study reveals that the low-frequency dielectric properties of the ferroelectric SrTiO(3) nanofibers are associated with the lowest transverse optical (TO) soft mode TO1 at 2.70 THz (90.0 cm(-1)), and that of the ferroelectric BaTiO(3) nanofibers are related to the lowest pair of transverse optical (TO) and longitudinal optical (LO) modes near 5.35 THz, which are both consistent with their bulk single-crystal and thin-film counterparts.

Journal
Journal of Nanoscience and Nanotechnology
Volume
11
Issue
11
Year
2011
Start Page
9636
URL
http://www.ingentaconnect.com/contentone/asp/jnn/2011/00000011/00000011/art00048
ISBN/ISSN
1533-4899; 1533-4880
DOI
10.1166/jnn.2011.5315