The electromagnetic properties of small metal particle mixtures
Abstract
The far infrared absorption coefficient of mixtures of small metal and insulating particles is addressed. The absorption coefficients of samples containing gold and palladium in an alumina host were measured from 5 to 150/cm. The palladium samples were then converted into PdH0.8 so that the electrical conductivity of the metal could be changed without affecting the geometric arrangement of the particles. The absorption coefficients of the hydrogenated palladium samples were compared with their unhydrogenated counterparts. Scanning electron micrographs revealed that the particles were aggregated into clusters. The theoretical calculations used the effective medium theory to find the conductivity of these clusters. The absorption coefficients of the mixtures were calculated from the effective dielectric function and the effective magnetic permeability. These quantities were obtained with the Maxwell Garnett approach. The electric and magnetic polarizabilities were calculated from Mie theory. The cluster size distributions were accounted for explicitly in the calculations. The absorption is strongly dependent on the geometric arrangement of the particles in the mixtures and only weakly on the electrical conductivity of the particles themselves.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1980
- Bibcode:
- 1980PhDT........86H
- Keywords:
-
- Infrared Absorption;
- Metal Particles;
- Mixtures;
- Absorptivity;
- Aluminum Oxides;
- Clumps;
- Electrical Resistivity;
- Electron Microscopy;
- Gold;
- Magnetic Permeability;
- Mie Scattering;
- Palladium;
- Communications and Radar