title: Terahertz response of ferroelectric nanofibers.
abstract: Far-infrared optical and dielectric properties of ferroelectric SrTiO3 and BaTiO3 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 SrTiO3 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 BaTiO3 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.
authors.affiliation: Center for Terahertz Waves, College of Precision Instrument and Optoelectronics Engineering, Tianjin University and the Key Laboratory of Opto-Electronics Information and Technical Science, Ministry of Education, Tianjin 300072, P. R. China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Tian
authors.forename: Kun
authors.initials: K
authors.lastname: Xin
authors.forename: Mingwei
authors.initials: M
authors.lastname: Wang
authors.forename: Jiaguang
authors.initials: J
authors.lastname: Han
authors.forename: Haizhen
authors.initials: H
authors.lastname: Wang
authors.forename: Z Ryan
authors.initials: ZR
authors.lastname: Tian
authors.forename: Weili
authors.initials: W
authors.lastname: Zhang