University of Oulu

Bagheri, M., Ibragimova, R., & Komsa, H.-P. (2021). Fermiology of two-dimensional titanium carbide and nitride MXenes. Physical Review B, 104(3), 035408. https://doi.org/10.1103/PhysRevB.104.035408

Fermiology of two-dimensional titanium carbide and nitride MXenes

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Author: Bagheri, Mohammad1; Ibragimova, Rina2; Komsa, Hannu-Pekka1,2
Organizations: 1Microelectronics Research Unit, University of Oulu, 90014 Oulu, Finland
2Department of Applied Physics, Aalto University, 00076 Aalto, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 1.7 MB)
Persistent link: http://urn.fi/urn:nbn:fi-fe202201132101
Language: English
Published: American Physical Society, 2021
Publish Date: 2022-01-13
Description:

Abstract

MXenes are a family two-dimensional transition-metal carbide and nitride materials, which often exhibit very good metallic conductivity and are thus of great interest for applications in, e.g., flexible electronics, electrocatalysis, and electromagnetic interference shielding. However, surprisingly little is known about the fermiology of MXenes, i.e., the shape and size of their Fermi surfaces, and its effect on the material properties. One reason for this may be that MXene surfaces are almost always covered by a mixture of functional groups, and studying Fermi surfaces of disordered systems is cumbersome. Here, we study fermiology of four common Ti-based MXenes as a function of the surface functional group composition. We first calculate the effective band structures of systems with explicit mixed surfaces and observe gradual evolution in the filling of the Ti-d band and resulting shift of Fermi level. We then demonstrate that these band structures can be closely approximated by using pseudohydrogenated surfaces, and also compare favorably to the experimental angle-resolved photoemission spectroscopy results. By modifying the pseudohydrogen charge we then proceed to plot Fermi surfaces for all systems and extract their properties, such as the Fermi-surface area and average Fermi velocity. These are in turn used to evaluate the electrical conductivity with the relaxation time fitted to experimentally measured conductivities.

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Series: Physical review. B
ISSN: 2469-9950
ISSN-E: 2469-9969
ISSN-L: 2469-9950
Volume: 104
Issue: 3
Article number: 035408
DOI: 10.1103/PhysRevB.104.035408
OADOI: https://oadoi.org/10.1103/PhysRevB.104.035408
Type of Publication: A1 Journal article – refereed
Field of Science: 114 Physical sciences
216 Materials engineering
Subjects:
Funding: We are grateful to the Academy of Finland for support under Academy Research Fellow funding No. 311058.
Copyright information: © 2021 American Physical Society.