Covellite is a metallic layered mineral with rather strong interlayer interaction. Recently, synthesis of covellite nanosheets of 3.2 nm thickness was reported (Du et al 2012 Nat. Commun. 3 1177), which raises the question: 'What is the thinnest possible covellite nanosheet?' Based on density functional/plane waves calculations, we have shown that graphene-like structure CuS (1L-CuS) is unstable but can be stabilized on a support. Here, however, we demonstrate that the three layered CuS (3L-CuS) with thickness of 0.773 nm (including the atomic radius of the outer plans atoms) is predicted to be intrinsically stable, as confirmed by phonon analysis and Born-Oppenheimer molecular dynamics simulations, with 3L-CuS about 0.15 eV per CuS less stable than the bulk. Interestingly, the electronic band structure shows metallic character with four bands crossing the Fermi level. The nature of chemical bonding is confirmed by a detailed topological analysis of the electron density.
Bibliographical noteFunding Information:
We would like to thank Vladimir Bačić for the fruitful discussions in the phonon dispersion results. Financial resources for this study were provided by the support of the following Brazilian agencies: Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG); Conselho Nacional para o Desenvolvimento Científico e Tecnológico (CNPq) and Coordenação de Aperfeiçoamento de Pessoal de Ensino Superior (CAPES); which are also gratefully acknowledged. The National Institute of Science and Technology for Mineral Resources, Water and Biodiversity has also supported this work - ACQUA-INCT (http://acqua-inct.org). Deutsche Forschungsgemeinschaft is thanked for financial support in the FlagERA project Trans2DTMD.
© 2016 IOP Publishing Ltd.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering