| Issue |
Microsc. Microanal. Microstruct.
Volume 6, Number 1, February 1995
|
|
|---|---|---|
| Page(s) | 99 - 111 | |
| DOI | https://doi.org/10.1051/mmm:1995110 | |
DOI: 10.1051/mmm:1995110
Phase Identification in Carbon and BN Systems by EELS
Herbert K. SchmidDiv. Materials Science and Technology, CSIR, Pretoria/RSA, South Africa
Abstract
Electron energy-loss spectroscopy measurements have
been made on carbon and BN polymorphs, as well as on a number
of borides, carbides and nitrides present in sintered cBN based
compacts. The similarity in crystal symmetry between carbon
and the isotructural BN system results in spectral similarities
in both the low-loss features and electron energy-loss near-edge
structure associated with the particular core-loss ionization
edges. ELNES features hold information on the nearest neighbour
environment of the excited atom in a given phase. It is shown
that the analysis of these features provides characteristic
coordination fingerprints for the identification of carbon and
BN allotropes. Similarly, the comparison of ELNES features associated
with B-K, C-K and N-K ionization edges provides fingerprints
for the identification of B in 
and
,
C in TiC and , and N in AlN, TiN and
BN, respectively. An attempt is made to quantify the fraction
of 
bonding in diamond-like carbon and cBN
based cutting tool material from the relative intensity of the
resonance in C-K and B-K ELNES, respectively.
7920K - Other electron surface impact phenomena.
6180M - Channelling, blocking and energy loss of particles.
6150K - Crystallographic aspects of polymorphic and order disorder transformations.
6160 - Crystal structure of specific inorganic compounds.
6155D - Crystal structure of specific nonmetallic elements.
6150E - Crystal symmetry: models and space groups, and crystalline systems and classes.
3520G - Molecular bond strengths, dissociation energies, hydrogen bonding.
6150L - Crystal binding.
Key words
bonds chemical -- boron compounds -- carbon -- crystal structure -- crystal symmetry -- electron energy loss spectra -- polymorphism -- phase identification -- EELS -- electron energy loss spectroscopy -- polymorphs -- sintered compacts -- borides -- carbides -- nitrides -- crystal symmetry -- low loss features -- electron energy loss near edge structure -- core loss ionization edges -- ELNES -- isostructural system -- nearest neighbour environment -- excited atom -- characteristic coordination fingerprints -- allotropes -- ionization edges -- sp sup 3 bonding -- diamond like C -- cutting tool material -- BN -- C -- TiB sub 2 -- B sub 4 C -- TiC -- AlN -- TiN
© EDP Sciences 1995