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conferenceseries
.com
Volume 3, Issue 2
ISSN: 2470-9905
Crystallography 2017
October 16-17, 2017
2
nd
International Conference on
October 16-17, 2017 | Chicago, USA
Applied Crystallography
Boron suboxide properties and low pressure growth
Glen A Slack
and
Kenneth E Morgan
Science Consulting, USA
B
oron Suboxide (B
6
O) is a compound semiconductor possessing α-rhombohedral Boron type structure (R3m) and is the second
most studied material of the Boron-Rich solids after B
4
C. The allowed phase width of B
6
O is expressed as B
12
(O
2
-xB
x
) where
0≤x≤1. In the stoichiometric unit cell of B
6
O, two oxygen atoms are positioned along the hexagonal <111> (c-axis) at the boron-
icosahedral interstitial sites 2c, with the single 1b central position left unoccupied. The oxygen atoms donate one electron each to the
boron icosahedra and compensate for the electron deficiency of pure α-B. The resulting short interatomic bond lengths and strong
covalent bonding establish the bulk properties of B
6
O, which possess the smallest unit cell volume of the α-boron derivatives. This
structure is different from the semi-metallic structure of B
4
C, where the 1b site is occupied and three interstitial atoms form a chain
along the c-axis. When stoichiometric (x=0) B
6
O is intrinsic high-resistivity semiconductor with an expected hole mobility at 300K
approaching 100 cm2V-1s-1 and an optical band gap of about 2.5 eV and a melting point of 2075
o
C. It is also a Super-Hard class
material with bulk modulus of 314 GPa and a Vickers hardness exceeding 45 GPa. Sub-stoichiometric crystals of B
6
O contain boron
atoms replacing interstitial oxygen atoms and possess diminished properties. We will present a low pressure method for producing
stoichiometrically correct B
6
O macroscopic crystals, contrasting this method with alternate approaches in the literature and discuss
applications for B
6
O which include nuclear detectors and cutting technologies.
Morgan.Kenneth@outlook.comStruct Chem Crystallogr Commun, 3:2
DOI: 10.21767/2470-9905-C1-003