Propagation distances of surface electromagnetic waves on Ni, Pd, Pt, and W metal surfaces

The propagation distances, Lsub(x), of surface electromagnetic waves (SEW) on Ni, Pd, Pt, and W were measured using the two-prism coupling technique at wavelengths from 9.3 to 10.6 μm. Metal samples consisted of films, deposited on glass substrates by electron beam deposition, and metal foils. The measured Lsub(x) values for the Pd and Pt films and Pt foil agree to within 20% of the calculated values from the two-media dispersion relation. The measured values of the propagation distance for the Ni film and foil and the W foil agree to within 50% of the calculated Lsub(x). Scanning electron microscope (SEM) photographs and Auger analysis indicate that film imperfections and foil surface roughness contributed to the lower propagation distances observed for Pt and Pd while imperfections, roughness, and oxidation contributed to the disagreement between measured and calculated propagation distance for Ni and W. (Auth.)