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Narrowband Microwave Dielectric Resonance and Negative Permittivity Behavior in Hydrogen‐Fired Al 2 O 3 –CuO Composites
Author(s) -
Calame Jeffrey P.,
Battat Jacob
Publication year - 2006
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2006.01306.x
Subject(s) - permittivity , materials science , microwave , dielectric , composite material , copper , resonance (particle physics) , drude model , copper oxide , relative permittivity , condensed matter physics , optoelectronics , metallurgy , atomic physics , physics , quantum mechanics
The frequency‐dependent microwave complex permittivity of composites based on an Al 2 O 3 –CuO system is investigated at room temperature. The composites are formed by solution infusion of copper precursors into a porous Al 2 O 3 matrix, followed by thermal decomposition to copper oxides and localized formation of copper aluminate compounds, and finally, H 2 firing. The material exhibits a strong amplitude, with relatively narrowband dielectric resonance in the microwave frequency regime at intermediate levels of mass gain, which is reminiscent of a plasmon resonance. Large mass gains cause negative permittivity behavior below 6 GHz, consistent with a collisional Drude model of a semiconducting oxide phase.