The structure of evaporated films of eight different metals in thicknesses from 30 to 500A has been observed in the electron microscope and correlated with their optical properties. The stable form of films thinner than a characteristic thickness was found to be aggregated. For each film the absorptions for wave-lengths in the visible were determined from the measured transmissions and reflections. The rate of formation is shown to affect the structure and the optical properties, slow rates in general giving more aggregated structure and increased light absorption.
The Garnett theory has been used to explain the peculiar variation with thickness of the optical properties of thin metallic films in terms of the observed structure of the films and the bulk properties of the metal. The presence or absence of absorption maxima and their change with wave-length can be predicted qualitatively on the basis of this theory for all the films studied.
© 1950 Optical Society of AmericaFull Article | PDF Article
OSA Recommended Articles
G. Henderson and C. Weaver
J. Opt. Soc. Am. 56(11) 1551-1559 (1966)
Archan Banerjee, Robert M. Heath, Dmitry Morozov, Dilini Hemakumara, Umberto Nasti, Iain Thayne, and Robert H. Hadfield
Opt. Mater. Express 8(8) 2072-2088 (2018)
V. V. Truong and G. D. Scott
J. Opt. Soc. Am. 67(4) 502-510 (1977)