Carbon-rich superhard ruthenium carbides from first-principles

Shipeng Zhao; Yali Yang; Jian Lu; Wei Wu; Sheng Sun; Xi Li; Xinluo Zhao; Shixun Cao; Jincang Zhang; Wei Ren

Materials & Design (Mar 2017)

Carbon-rich superhard ruthenium carbides from first-principles

Shipeng Zhao,
Yali Yang,
Jian Lu,
Wei Wu,
Sheng Sun,
Xi Li,
Xinluo Zhao,
Shixun Cao,
Jincang Zhang,
Wei Ren

Affiliations

Shipeng Zhao: International Centre for Quantum and Molecular Structures, Physics Department, Shanghai University, Shanghai 200444, China
Yali Yang: International Centre for Quantum and Molecular Structures, Physics Department, Shanghai University, Shanghai 200444, China
Jian Lu: International Centre for Quantum and Molecular Structures, Physics Department, Shanghai University, Shanghai 200444, China
Wei Wu: International Centre for Quantum and Molecular Structures, Physics Department, Shanghai University, Shanghai 200444, China
Sheng Sun: Material Genome Institute, Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai 200444, China
Xi Li: State Key Laboratory of Advanced Special Steel, Shanghai University, Shanghai 200072, China
Xinluo Zhao: International Centre for Quantum and Molecular Structures, Physics Department, Shanghai University, Shanghai 200444, China
Shixun Cao: International Centre for Quantum and Molecular Structures, Physics Department, Shanghai University, Shanghai 200444, China; Material Genome Institute, Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai 200444, China
Jincang Zhang: Material Genome Institute, Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai 200444, China
Wei Ren: International Centre for Quantum and Molecular Structures, Physics Department, Shanghai University, Shanghai 200444, China; Material Genome Institute, Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai 200444, China; Corresponding author.

Journal volume & issue: Vol. 117
pp. 353 – 362

Abstract

Read online

Compounds formed by transition metals and light elements have attracted increasing attention owing to superior functionalities. Here, high throughput first-principles calculations are employed to investigate the crystal structures and physical properties of ruthenium carbides with various stoichiometries. It is found that the R3¯m-Ru2C, R3¯m-RuC, P3¯m1-Ru2C3, P3¯m1-RuC2, P3¯m1-RuC3 and C2/c-RuC4 are the ground states for the respective chemical compositions at ambient pressure, from a systematical investigation of both thermodynamic and mechanical stabilities, as well as phonon dispersions. Further calculations indicate that P3¯m1-RuC3 and P63/mmc-RuC4 are ultra-incompressible with high bulk and shear modulus. Subsequent empirical calculations predict that the carbon-rich P3¯m1-RuC3 and P63/mmc-RuC4 are superhard materials with a large Vickers hardness of 45.1 GPa and 41.5 GPa, respectively. In addition, a strong covalent CC bonding was observed from the electronic localization function contours of all the ground states, which is crucial for their excellent mechanical properties. Keywords: First-principles calculations, Dynamical stabilities, Mechanical properties

Published in Materials & Design

ISSN: 0264-1275 (Print); 1873-4197 (Online)
Publisher: Elsevier
Country of publisher: United Kingdom
LCC subjects: Technology: Electrical engineering. Electronics. Nuclear engineering: Materials of engineering and construction. Mechanics of materials
Website: https://www.journals.elsevier.com/materials-and-design

About the journal