Pressure dependent structural, dynamical, mechanical and electronic properties of magnesium dicarbide. Issue 4 (16th February 2023)

• Record Type: Journal Article
• Authors: Wu, HaiYing; Chen, YaHong; Liu, Zi Jiang; Han, XiangYu; Yin, PengFei
• Is Part Of: Philosophical magazine. Volume 103:Issue 4(2023)
• Page Start: 369
• Page End: 390
• Publication Date: 2023-02-16
• Subjects: High pressure -- mechanical properties -- dynamical properties -- electronic properties; Condensed matter -- Periodicals; Physics -- Periodicals; Matière condensée -- Périodiques; Physique -- Périodiques; 530.41
• DOI: 10.1080/14786435.2022.2152121
• Languages: English
• ISSNs: 1478-6435

Abstract

ABSTRACT: Magnesium dicarbide (MgC2 ) at high pressure has been systematically investigated using the first-principle methods. Ten possible structures were studied and three of them (Cmcm, C2/m, P-3m1) were found to be dynamically and mechanically stable under the given pressure. The calculated formation enthalpies indicated that the Cmcm structure was thermodynamically unstable while the C2/m and P-3m1 structures were thermodynamically stable. The interesting thing was that the P-3m1 structure of MgC2 could also be as potential hard materials owing to their Vickers hardness closing to 40 GPa with increasing pressure. The Cmcm and C2/m structures presented ductile behaviour while P-3m1 structure displayed brittle character. The elastic anisotropy of Young's modulus E and shear modulus G became smaller with the increasing pressure, and the P-3m1 structure possessed a lower anisotropy in E and G than Cmcm and C2/m structures. The Cmcm and C2/m structures of MgC2 had metallic characteristic; however, the P-3m1 structure of MgC2 was semiconductor with an indirect band gap.