Speaker
David Crandles
(Brock University)
Description
Recently, several papers reported the discovery of giant permittivity and low dielectric loss in (Nb+In) co-doped TiO$_2$. A series of tests was performed which included the measurement of the frequency dependence of the dielectric permittivity and ac conductivity of co-doped (Nb+In)TiO$_2$ as a function of electrode type, sample thickness and temperature. The data suggest that the measurements are strongly affected by the electrodes. The consistency between four contact van der Pauw dc conductivity measurements and bulk conductivity values extracted from two contact ac conductivity measurements suggest that the values of colossal permittivity are, at least in part, a result of Schottky barrier depletion widths that depend on electrode type and temperature.
Author
David Crandles
(Brock University)
Co-authors
Dimitri Nuzhny
(Insitute of Physics, The Czech Academy of Sciences)
Jan Petzelt
(Institute of Physics, The Czech Academy of Sciences)
Jan Prokes
(Charles University in Prague, Faculty of Mathematics and Physics)
Maxim Savinov
(Institute of Physics, The Czech Academy of Sciences)
Stanislav Kamba
(Institute of Physics, The Czech Academy of Sciences)
Susan Yee
(Brock University)
