Diamond films were deposited on alumina substrates both by microwave p
lasma chemical vapor deposition and hot filament chemical vapor deposi
tion techniques. The qualities of deposited films were characterized b
y X-ray diffraction and Raman scattering spectrometry. The dielectric
properties of the diamond film/alumina composites were measured, and w
ere compared with the results also calculated by the model of series c
apacitors. (C) 1997 Elsevier Science S.A.