Abstract
A growth mechanism for submicrometer grains in diamondlike carbon films has been investigated. Films were formed by laser deposition on quartz substrates at
20
-
573
K
. Atomic force microscopy shows that films deposited at
20
-
100
K
consist of a matrix assembled from
40
nm
nanoparticles that further aggregate into
400
-
500
nm
grains which become embedded in the matrix. Nanohardness measurements show that these embedded grains possess a lower hardness than that of the matrix. Electronic structure obtained from resonant Raman spectra shows a remarkable clustering of
s
p
2
bonds in the
s
p
3
bonded matrix. It is believed that the
s
p
2
bonded phase is concentrated in these submicrometer grains. X-ray photoelectron spectra show that this segregated structure has an enhanced affinity for oxygen.