Raman scattering in transition metal dichalcogenides MTe2 (M = Mo, W)

Abstract

We performed comparable polarized Raman scattering studies of MoTe2 and WTe2. By rotating crystals to tune the angle between the principal axis of the crystals and the polarization of the incident/scattered light, we obtained the angle dependence of the intensities for all the observed modes, which is perfectly consistent with careful symmetry analysis. Combining these results with first-principles calculations, we clearly identified the observed phonon modes in the different phases of both crystals. Fifteen Raman-active phonon modes (10Ag+5Bg) in the high-symmetry phase 1T'-MoTe2 (300 K) were well assigned, and all the symmetry-allowed Raman modes (11A1+6A2) in the low-symmetry phase Td-MoTe2 (10 K) and 12 Raman phonons (8A1+4A2) in Td-WTe2 were observed and identified. The present work provides basic information about the lattice dynamics in transition-metal dichalcogenides and may shed some light on the understanding of the extremely large magnetoresistance (MR) in this class of materials.

16 pages, 4 figures, 1 table, 47 references

References in corpus (8)

• Titanic Magnetoresistance in WTe2
• Phonon and Raman scattering of two-dimensional transition metal dichalcogenides from monolayer, multilayer to bulk material
• Electronic structure basis for the titanic magnetoresistance in WTe${}_2$
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• Anisotropic giant magnetoresistance in NbSb2
• Electron scattering in tantalum monoarsenide
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Cited by in corpus (1)

• Enhanced ultrafast relaxation rate in the Weyl semimetal phase of $\mathbf{MoT}{\mathbf{e}}_2$ measured by time-and angle-resolved photoelectron spectroscopy