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Topology of charge density and elastic anisotropy of Ti3SiC2 polymorphs

Published online by Cambridge University Press:  03 March 2011

R. Yu*
Affiliation:
Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
X.F. Zhang
Affiliation:
Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
L.L. He
Affiliation:
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People's Republic of China
H.Q. Ye
Affiliation:
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People's Republic of China
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

Using an all-electron, full potential first-principles method, we have investigated the topology of charge density and elastic anisotropy of Ti3SiC2 polymorphs comparatively. By analyzing the charge density topology, it was found that the Ti–Si bonds are weaker in β than in α, resulting in a destabilizing effect and lower Young’s modulus in directions between a and c axes for β. On the other hand, the Si–C bonds (absent in α) are formed in β in the c direction. The formation of the Si–C bonds not only mitigates the destabilizing effect of the weaker Ti–Si bonds, but also results in larger Young’s modulus in the c direction. In contrast to the high elastic anisotrophy, the elastic anisotropy of Ti3SiC2 is very low.

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Articles
Copyright
Copyright © Materials Research Society 2005

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