Probing electron-phonon and phonon-phonon coupling in type-II Dirac semi-metal NiTe2 via temperature-dependent Raman spectroscopy

James, MT and Mandal, S and Sebastian, NK and Mishra, P and Ganesan, R and Kumar, PSA (2023) Probing electron-phonon and phonon-phonon coupling in type-II Dirac semi-metal NiTe2 via temperature-dependent Raman spectroscopy. In: Journal of Physics Condensed Matter, 35 (12).

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Abstract

We report the temperature-dependent structural characterization of type-II Dirac semimetal NiTe2 in the form of a bulk single crystal and a nanoflake (200 nm thick). Detailed x-ray diffraction study along with Rietveld refinement analysis reveals superior crystallinity and linear thermal expansion coefficient (α T) of 5.56 × 10−6 and 22.5 × 10−6 K−1 along a or b and c lattice directions, respectively. Temperature evolution of Raman spectra shows non-linear variations in the phonon frequency and full-width half maxima of the out-of-plane A 1g and in-plane Eg modes. Raman mode E 2g1 , corresponding to an in-plane vibration, disappears on decreasing the thickness from bulk to nanoflake. Quantitative analysis with anharmonic model yields dominating electron-phonon interaction over phonon-phonon interaction mediated by three- and four-phonon processes.

Item Type:	Journal Article
Publication:	Journal of Physics Condensed Matter
Publisher:	Institute of Physics
Additional Information:	The copyright for this article belongs to Institute of Physics.
Keywords:	Electron diffraction; Electron-phonon interactions; Nickel compounds; Raman spectroscopy; Rietveld refinement; Single crystals; Thermal expansion, Dirac semimetal; Electron phonon; Nano-flakes; Phonon-phonon couplings; Semi-metals; Structural characterization; Temperature dependent; Temperature-dependent Raman spectroscopies; Type II; X-ray diffraction, Crystallinity
Department/Centre:	Division of Interdisciplinary Sciences > Centre for Nano Science and Engineering Division of Physical & Mathematical Sciences > Physics
Date Deposited:	16 Feb 2023 03:40
Last Modified:	16 Feb 2023 03:40
URI:	https://eprints.iisc.ac.in/id/eprint/80283

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