Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Role of microstructure and structural disorder on tribological
  properties of polycrystalline diamond films   Polycrystalline diamond films with systematic change in microstructure that
varies from microcrystalline to nanocrystalline structure are synthesized on Si
by hot filament chemical vapor deposition. The morphology and structural
properties of the grown diamond films are analyzed using field emission
scanning electron microscope (FESEM), atomic force microscope (AFM), X-ray
diffraction and Raman spectroscopy. The average roughness and grain size of the
diamond films decrease with increase in CH4 to H2 ratio from 0.5 to 3 %. Also,
structural disorder in these diamond films increases with decrease in grain
size as evidenced from Raman spectroscopy. The coefficient of friction (CoF) is
found to be very low for all the films. However, the average CoF is found to
increase from 0.011 +/-0.005 to 0.03 +/- 0.015 as the grain size decrease from
~ 1 micron down to ~20 nm. Post analysis of wear track by FESEM, AFM based
nanoscale friction and Raman spectroscopy reveal that microcrystalline diamond
undergoes shear induced amorphization with negligible wear rate while
nanocrystalline diamond films undergo shear induced plastic deformation without
amorphization. A comprehensive mechanism for the observed CoF is discussed in
the framework of microstructure, structural disorder and shear induced
tribo-chemical reactions at the sliding interface.

3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
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The categories of this paper are: hep-lat
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
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The categories of this paper are: solv-int
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The categories of this paper are: chao-dyn
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The categories of this paper are: plasm-ph
24
The categories of this paper are: dg-ga