The structural evolution of boron carbide via ab initio calculations
The distribution of boron and carbon atoms in boron carbide ( B 4 C ) , the third hardest naturally occurring material, is a hotly debated subject. In the current work, an ab initio approach is applied to the entire composition range of boron carbide ( ∼ 8 - 20 at. % C ) to determine what disorderin...
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| Published in | Applied physics letters Vol. 91; no. 23; pp. 231915 - 231915-3 |
|---|---|
| Main Authors | , , |
| Format | Journal Article |
| Language | English |
| Published |
American Institute of Physics
03.12.2007
|
| Online Access | Get full text |
| ISSN | 0003-6951 1077-3118 |
| DOI | 10.1063/1.2818661 |
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| Summary: | The distribution of boron and carbon atoms in boron carbide
(
B
4
C
)
, the third hardest naturally occurring material, is a hotly debated subject. In the current work, an
ab initio
approach is applied to the entire composition range of boron carbide
(
∼
8
-
20
at.
%
C
)
to determine what disordering mechanisms are responsible for such a large single-phase region. Based on the correctly predicted crystal structures, enthalpy of formation, and infrared phonon modes, we reveal direct evidence in support of a new defect model for boron carbide, where mixing occurs in the icosahedron for carbon-rich compositions and in the chain for boron-rich compositions. |
|---|---|
| ISSN: | 0003-6951 1077-3118 |
| DOI: | 10.1063/1.2818661 |