Title

Energetics of Cu adsorption and intercalation at graphite step edges

Publication Date

3-11-2019

Department

Ames Laboratory; Chemistry; Materials Science and Engineering; Physics and Astronomy

Campus Units

Ames Laboratory, Chemistry, Materials Science and Engineering, Physics and Astronomy

OSTI ID+

1502874

Report Number

IS-J 9815

DOI

10.1103/PhysRevB.99.115415

Journal Title

Physical Review B

Volume Number

99

Issue Number

11

First Page

115415

Abstract

To assess the energetics of Cu intercalation on defective graphite, the chemical potentials and binding energies for Cu at graphite step edges are calculated for three main configurations: an isolated atom, a chain, and an atom attached to a chain. As expected, for Cu interacting directly with a graphite step edge, the strength of interaction depends on the stability of the step, with Cu binding more strongly at a less-stable step. However, the relationship is reversed when considering binding of a Cu atom attached to a chain. Taken together, these trends mean that if the graphite step is less stable, as for the zigzag step, then decorating the step with a Cu chain facilitates intercalation by additional Cu atoms (which are less strongly bound to the decorated step). For more stable steps, intercalation is optimal without decoration. We also calculate the diffusion barrier for atomic Cu on top of the graphite terrace and, in the uppermost gallery, find values of 0.008 and 0.021 eV, respectively. These values are very small, indicating that the minimum barrier for a Cu atom to detach from a step and move to a terrace or gallery is dominated by the difference in binding energies. For intercalation, this minimum barrier is 1.4 to 3.1 eV and depends strongly on step configuration.

DOE Contract Number(s)

AC02-05CH11231; AC02-07CH11358; ACI-1548562

Language

en

Department of Energy Subject Categories

36 MATERIALS SCIENCE

Publisher

Iowa State University Digital Repository, Ames IA (United States)

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