Mechanical properties of technetium carbides. (May 2015)

• Record Type: Journal Article
• Authors: Bian, Y.; Liu, X.; Li, A.; Wang, S.; Liang, Y.
• Is Part Of: Materials research innovations. Volume 19:Number 5(2015)
• Page Start: S5-178
• Page End: S5-181
• Publication Date: 2015-05
• Subjects: Materials -- Research -- Periodicals; Matériaux -- Recherche -- Périodiques; 620.1105
• DOI: 10.1179/1432891714Z.0000000001071
• Languages: German
• ISSNs: 1432-8917

Abstract

<abstract> <title> <x content-type="archive" xml:space="preserve">Abstract</x> </title> <p>The mechanical properties and their electronic origins for technetium carbides have been investigated using first-principles calculations on the basis of density functional theory. The two hexagonal phases are found to have very high bulk modulus and Vickers hardness, making them ultra-low compressible and hard materials. In addition, both exhibit metallic features. The results indicate that their electronic structures are dominated by a strong hybridisation between the non-metal C-2p and metal Tc-4d states, which demonstrates strongly covalent characteristics. These directionally covalent bonds, as well as high valence electron concentration, give rise to low compressibility and high hardness. Therefore, a combination of high hardness, intense stiffness and good conductivity suggests that technetium carbides could find particular applications under extreme conditions of high temperature and pressure.</p> </abstract>