Lj. Martinez-miranda et al., Nanostructural study of the thermal transformation of diamond-like amorphous carbon into an ultrahard carbon nanocomposite, APPL PHYS L, 79(4), 2001, pp. 542-544
We studied the structural transformation of diamond-like amorphous carbon (
a-C) films into ultrahard carbon nanocomposites via postannealing to 600 de
greesC using transmission electron microscopy, x-ray reflectivity, and smal
l-angle scattering. Film density decreases monotonically above 200 degreesC
. Film surfaces roughen upon annealing to 300 degreesC; however, a-C recove
rs its smoothness with higher temperature annealing. Finally, there exists
some quasiperiodic nanostructural feature with a lattice spacing that incre
ases with annealing, correlating well with purely a-C nanocomposite structu
res imaged from samples annealed at 600 degreesC. We propose that these ann
ealing-induced nanostructural changes are a derivative of localized stress
fields in as-grown a-C films. (C) 2001 American Institute of Physics.