2016 CAP Congress / Congrès de l'ACP 2016

Colossal Permittivity in In + Nb co-doped TiO2

14 Jun 2016, 19:46

2m

SITE Atrium (University of Ottawa)

Poster (Student, Not in Competition) / Affiche (Étudiant(e), pas dans la compétition) Condensed Matter and Materials Physics / Physique de la matière condensée et matériaux (DCMMP-DPMCM) DCMMP Poster Session with beer / Session d'affiches, avec bière DPMCM

Speaker

Susan Yee

Description

In $+$ Nb co-doped TiO${}_2$ has been previously investigated and shown to display colossal permittivity (${ϵ}_1>{10}^3$) for frequencies less than or equal to 1 MHz using impedance spectroscopy. In this work the lattice vibrational contribution to the low frequency dielectric function is studied in ceramic samples at the 0\%,5\%, and 10\% doping level using temperature-dependent reflectance spectroscopy. It is found that the soft mode behaviour exhibited by the lowest frequency infrared ibrational mode in pure TiO${}_2$ is not strongly affected by the co-doping. There is a large discrepancy between the ${ϵ}_1$ measured at the lowest far infrared frequencies in this reflectance spectroscopy study ($\approx 1.5$ THz) and the value measured below 1 MHz.