TY - JOUR
T1 - Compositional and Structural Atomistic Study of Amorphous Si-B-N Networks of Interest for High-Performance Coatings
AU - Al-Ghalith, Jihong
AU - Dasmahapatra, Atreyi
AU - Kroll, Peter
AU - Meletis, Efstathios
AU - DumitricǍ, Traian
N1 - Publisher Copyright:
© 2016 American Chemical Society.
PY - 2016/10/27
Y1 - 2016/10/27
N2 - We explore by computational modeling the effects of boron-nitrogen (BN) composition on the thermal and mechanical properties of amorphous silicon-boron-nitride (Si-B-N), a synthetic ceramic material with superior thermal protection, mechanical attributes, and oxidation resistance at high temperatures. Network-derived Si-B-N models optimized with ab initio molecular dynamics serve as input structures for classical molecular dynamics simulations. Atomistic Green-Kubo simulations on relaxed supercells and structural relaxations on strained cells are used to screen the thermal and mechanical properties of a collection of network structures with low enthalpies of formation. We find that when the material is composed of well-mixed parts rather homogeneously spread within the material, the thermal conductivity and elastic constants are isotropic and exhibit a weak dependence on composition and network structure. In contrast, when separation into BN-rich layers occurs, the material exhibits anisotropic behavior, with an increase in thermal conductivity along the layer direction and decrease in elastic constant in the cross-layer direction. The insights provided into the composition-structure-property relationships can be useful for the rational design of amorphous Si-B-N materials targeting high-performance coating applications.
AB - We explore by computational modeling the effects of boron-nitrogen (BN) composition on the thermal and mechanical properties of amorphous silicon-boron-nitride (Si-B-N), a synthetic ceramic material with superior thermal protection, mechanical attributes, and oxidation resistance at high temperatures. Network-derived Si-B-N models optimized with ab initio molecular dynamics serve as input structures for classical molecular dynamics simulations. Atomistic Green-Kubo simulations on relaxed supercells and structural relaxations on strained cells are used to screen the thermal and mechanical properties of a collection of network structures with low enthalpies of formation. We find that when the material is composed of well-mixed parts rather homogeneously spread within the material, the thermal conductivity and elastic constants are isotropic and exhibit a weak dependence on composition and network structure. In contrast, when separation into BN-rich layers occurs, the material exhibits anisotropic behavior, with an increase in thermal conductivity along the layer direction and decrease in elastic constant in the cross-layer direction. The insights provided into the composition-structure-property relationships can be useful for the rational design of amorphous Si-B-N materials targeting high-performance coating applications.
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U2 - 10.1021/acs.jpcc.6b07507
DO - 10.1021/acs.jpcc.6b07507
M3 - Article
AN - SCOPUS:84994030766
SN - 1932-7447
VL - 120
SP - 24346
EP - 24353
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 42
ER -