RT journal article
T1 Divergence of the dielectric constant in ultrathin granular metal films near the percolation threshold
A1 Bakkali, Hicham
A1 Blanco Ollero, Eduardo
A1 Lofland, S.E.
A1 Domínguez, M.
A2 Física de la Materia Condensada
K1 percolation
K1 tunneling conduction
K1 optical conductivity
AB We report on the electronic and optical properties of ultrathin granular films. We demonstrate that the static dielectric constant increases with thickness in the dielectric regime and diverges at the critical thickness, as predicted by classical percolation theory. However, for thicker samples, the dc conductivity does not obey scaling laws due to the presence of tunneling conduction. In this region the dielectric constant is positive, and the electronic transport is not metallic but can be described by Jonscher's universal power law, even though there is a Drude-like response indicating the presence of free charge carriers. Only for thicker films when the dielectric constant becomes negative is there metallic conduction.
PB IOP PUBLISHING LTD
SN 1367-2630
YR 2020
FD 2020-08
LK http://hdl.handle.net/10498/23696
UL http://hdl.handle.net/10498/23696
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 11-nov-2026