# name
Tribological Properties of Fluorinated Amorphous Carbon Thin Films

# metadata.dc.description.abstract[].value
The peculiar electronic configuration of carbon atoms, 1s2 2s2 2p2, and the small energy
difference between their 2p and 2s orbitals, compared to the binding energy of the carbon
bonds, allow the electrons to rearrange in s and p mixed orbitals that enhance the binding
energy with other atoms. This process is called hybridization and produces three different
types of orbitals: sp = s + p, sp2 = s + p + p and sp3 = s + p + p + p.
Each different bonding state corresponds to a certain structural arrangement: sp bonding
gives rise to chain structures (with two σ bonds and two π bonds), sp2 bonding conforms
onto planar structures (three σ bonds and one π bond) and finally sp3 bonding produces
tetrahedrical structures (four σ bonds). The p orbitals that form π bonds overlap less than the
orbitals forming σ bonds. The reduced overlapping makes π bonds weaker than σ bonds.
However, a number of scenarios are possible. Sometimes, as in ethene (C2H4), a σ and π
bond combine producing a stronger bond between carbon atoms. This is called a double
bond: C=C. Triple bonds consist of a σ bond and two π bonds, as in ethyne (C2H2). Although
chemically stronger thanks to double bonds, the mechanical stability obtained with sp2
hybridization in solids is limited, due to the planar geometry. Instead, sp3 hybridization
allows the creation of a three dimensional network of σ bonds.

# metadata.dc.rights[].value
cc by-nc-sa (c) Rubio Roy, Miguel et al., 2011

# metadata.dc.source[].value
Llibres / Capítols de llibre (Física Aplicada)

# metadata.dc.title[].value
Tribological Properties of Fluorinated Amorphous Carbon Thin Films