Microstructures of Amorphic Diamond™ Films Deposited by Laser-Ablation

Abstract

ABSTRACTMicrostructures of Amorphic Diamond™ films deposited by laser ablation method were investigated using transmission electron microscopy. The AD films matrix was homogeneous with a sp3-type bonding fraction of 40%∼45% confirmed by electron energy-loss spectroscopy. The sp3 bonding fraction decreased monotonically with increasing annealing temperature. The main inhomogeneity in Amorphic Diamond™ was observed to be particulates of high density (>105/cm2) distributed through the depth of the film. Particulate size ranged from ∼10nm to a few μm and most of them were identified to be graphite. Large particles (>0.5μm) were agglomerates of smaller graphite crystallites. Possible mechanisms for cold field emission are discussed based on the microstructures observed in these AD films.