Publication Date:
2020
Description:
〈p〉Publication date: April 2020〈/p〉
〈p〉〈b〉Source:〈/b〉 Journal of Physics and Chemistry of Solids, Volume 139〈/p〉
〈p〉Author(s): Zhongzheng Guo, Xianbang Jiang〈/p〉
〈div xml:lang="en"〉
〈h5〉Abstract〈/h5〉
〈div〉〈p〉In order to obtain a better understanding of the mechanical behavior and optical properties of cubic transition-metal carbides TM〈sub〉4〈/sub〉C〈sub〉3〈/sub〉 (TM = V, Nb, Ta), we explored the anisotropies of their elastic properties, thermal conductivities, and complex dielectric functions based on first-principles calculations. The phase stabilities of the carbides were analyzed based on their formation enthalpy and the results indicated that they are energetically stable, where the phase stability sequence is: Ta〈sub〉4〈/sub〉C〈sub〉3〈/sub〉 〉 Nb〈sub〉4〈/sub〉C〈sub〉3〈/sub〉 〉 V〈sub〉4〈/sub〉C〈sub〉3〈/sub〉. Systematic investigations of the elastic properties of the single-crystal and polycrystalline forms showed that the anisotropy of the elastic properties follows the sequence: Ta〈sub〉4〈/sub〉C〈sub〉3〈/sub〉 〉 V〈sub〉4〈/sub〉C〈sub〉3〈/sub〉 〉 Nb〈sub〉4〈/sub〉C〈sub〉3〈/sub〉. Moreover, we predicted the sound velocities and Debye temperatures, minimum thermal conductivities, optical properties, and their anisotropies for the cubic TM〈sub〉4〈/sub〉C〈sub〉3〈/sub〉 (TM = V, Nb, Ta) carbides, and the results indicated that all are anisotropic. Finally, we determined the sequences of the anisotropies of the minimum thermal conductivities and optical properties.〈/p〉〈/div〉
〈/div〉
〈h5〉Graphical abstract〈/h5〉
〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S002236971931861X-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉
Print ISSN:
0369-8726
Electronic ISSN:
1879-2553
Topics:
Chemistry and Pharmacology
,
Physics
