Pressure-induced electronic topological transition in Sb₂S₃

Abstract

Pressure induced electronic topological transitions in the wide band gap semiconductor Sb 2 S 3 (E g = 1.7-1.8 eV) with similar crystal symmetry (SG: Pnma) to its illustrious analog, Sb 2 Se 3 , has been studied using Raman spectroscopy, resistivity and the available literature on the xray diffraction studies. In this report, the vibrational and the transport properties of Sb 2 S 3 have been studied up to 22 GPa and 11 GPa, respectively. We observed the softening of phonon modes A g (2), A g (3) and B 2g and a sharp anomaly in their line widths at 4 GPa. The resistivity studies also shows an anomaly around this pressure. The changes in resistivity as well as Raman line widths can be ascribed to the changes in the topology of the Fermi surface which induces the electron-phonon and the strong phonon-phonon coupling, indicating a clear evidence of the electronic topological transition (ETT) in Sb 2 S 3 . The pressure dependence of a/c ratio plot obtained from the literature showed a minimum at ~ 5 GPa, which is consistent with our high pressure Raman and resistivity results. Finally, we give the plausible reasons for the non-existence of a non-trivial topological state in Sb 2 S 3 at high pressures.

Structural properties of Sb2S3 under pressure: evidence of an electronic topological transition

“…We can resolve ten broad bands in our Raman spectra ( Fig. 2 ), which is consistent with the reported literature 16 22 23 . The mode assignment is adopted from the polarization studies of Sereni et al .…”

“…Overall, we have detected two phase transitions at 5 GPa and 15 GPa. The first transition is manifested via compressibility changes in several structural parameters, an observation which correlates strongly with the reported ETT 16 . As for the second transition at 15 GPa, this new phase could not be identified due to the onset of structural disorder above 20 GPa.…”

“…A similar ETT was recently observed for Sb 2 S 3 by means of Raman spectroscopic and resistivity probes near 5 GPa, with a second phase transition following at 20 GPa 16 . Even though a x-ray diffraction (XRD) study of Sb 2 S 3 up to 10 GPa showed the persistence of the Pnma phase up to that pressure 17 , the mechanism of ETT at 5 GPa, the detection of the second transition at 20 GPa, as well as the possibility of additional structural modifications upon further compression 15 18 19 20 , calls for an updated structural investigation of Sb 2 S 3 in a more extended pressure range.…”

“…The M2 feature was also detected in the study of Sorb et al . above 20 GPa 16 . Beyond 15 GPa, however, the Raman modes exhibit pronounced broadening; consequently, the Raman spectra become rather featureless at 22 GPa [ Fig.…”

Structural, vibrational, and electrical properties of 1T−TiTe2 under hydrostatic pressure: Experiments and theory

“…Raman linewidth studies could provide the information about the phonon-phonon interactions and the excitation-phonon interactions such as electron-phonon, spin-phonon coupling existing in the system. [45][46][47][48][49] Therefore, we have carefully analyzed the FWHM of A1g and Eg modes and are shown in the Fig. 8.…”