Issue 21, 2016

Catenation of carbon in LaC2 predicted under high pressure

Abstract

Carbon has the capability of forming various bonding states that affect the structures and properties of transition metal carbides. In this work, structural search was performed to explore the structural diversity of LaC2 at pressures of 0.0–30.0 GPa. Five stable structures of LaC2 reveal a variety of carbon structural units ranging from a dimer to bent C3, zigzag C4 and armchair polymer chains. A series of pressure-induced structural transformations are predicted, I4/mmm (i.e. experimental α phase) → C2/cPnmaPmma, which involve the catenation of carbon from a dimer to zigzag C4 units and further to armchair polymer chains. The bent C3 unit appears in a novel Immm structure. This structure is the theoretical ground state of LaC2 under ambient conditions, but is kinetically inaccessible from the experimental α phase. LaC2 becomes thermodynamically metastable relative to La2C3 + diamond above 17.1 GPa, and eventually decomposes into constituent elements above 35.6 GPa. The presented results indicate that catenation of carbon can be realized even in simple inorganic compounds under nonambient conditions.

Graphical abstract: Catenation of carbon in LaC2 predicted under high pressure

Supplementary files

Article information

Article type
Paper
Submitted
03 Mar 2016
Accepted
28 Apr 2016
First published
28 Apr 2016

Phys. Chem. Chem. Phys., 2016,18, 14286-14291

Author version available

Catenation of carbon in LaC2 predicted under high pressure

C. Su, J. Zhang, G. Liu, X. Wang, H. Wang and Y. Ma, Phys. Chem. Chem. Phys., 2016, 18, 14286 DOI: 10.1039/C6CP01484D

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements