Pressure-induced isostructural electronic topological transitions in 2H-MoTe2: x-ray diffraction and first-principles study

• Published in: Journal of physics. Condensed matter Vol. 33; no. 6; p. 065402
• Main Authors: Bera, Achintya, Singh, Anjali, Gupta, Satyendra Nath, Glazyrin, K, Muthu, D V S, Waghmare, U V, Sood, A K
• Format: Journal Article
• Language: English
• Published: IOP Publishing 10.02.2021
• Subjects: density functional theory; electronic topological transition; high pressure; Lifshitz transition; transition metal dichalcogenide; x-ray diffraction
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/1361-648X/abaeac

Synchrotron x-ray diffraction measurements on powder 2H-MoTe2 (P63/mmc) up to ∼46 GPa have been performed along with first-principles based density functional theoretical analysis to probe the isostructural transition in low pressure regime and two electronic topological transitions (ETT) of Lifshitz-type in high pressure regime. The low pressure isostructural transition at ∼7 GPa is associated with the lattice parameter ratio c/a anomaly and the change in the compressibility of individual layers. The pressure dependence of the volume by linearizing the Birch-Murnaghan equation of state as a function of Eulerian strain shows a clear change of the bulk modulus at the ETT pressure of ∼20 GPa. The minimum of c/a ratio around 32 GPa is associated with the change in topology of electron pockets marked as second ETT of Lifshitz-type. We do not observe any structural transition up to the maximum applied pressure of ∼46 GPa under quasi-hydrostatic condition.