English

Pressure-induced optical anisotropy of HfS$_2$

Materials Science 2024-11-01 v1

Abstract

The effect of pressure on Raman scattering (RS) in the bulk HfS2_2 is investigated under hydrostatic and non-hydrostatic conditions. The RS lineshape does not change significantly in the hydrostatic regime, showing a systematic blueshift of the spectral features. In a non-hydrostatic environment, seven peaks emerge in the spectrum (PP=7 GPa) dominating the lineshape up to PP=10.5 GPa. The change in the RS lineshape manifests a pressure-induced phase transition in HfS2_2. The simultaneous observation of both low-pressure (LP) and high-pressure (HP) related RS peaks suggests the corresponding coexistence of two different phases over a large pressure range. We found that the HP-related phase is metastable, persisting during the decompression cycle down to PP=1.2 GPa with the LP-related features finally recovering at even lower pressures. The angle-resolved polarized RS (ARPRS) performed under PP=7.4 GPa revealed a strong in-plane anisotropy of both the LP-related A1g_{1g} mode and the HP peaks. The anisotropy is related to the possible distortion of the structure induced by the non-hydrostatic component of the pressure. We describe the obtained results by the influence of the non-hydrostatic pressure on the observed phase transition. We interpret our results in terms of a distorted PnmaPnma phase as a possible HP induced structure of HfS2_2.

Keywords

Cite

@article{arxiv.2402.19040,
  title  = {Pressure-induced optical anisotropy of HfS$_2$},
  author = {Igor Antoniazzi and Tomasz Woźniak and Amit Pawbake and Natalia Zawadzka and Magdalena Grzeszczyk and Zahir Muhammad and Weisheng Zhao and Jordi Ibáñez and Clement Faugeras and Maciej R. Molas and Adam Babiński},
  journal= {arXiv preprint arXiv:2402.19040},
  year   = {2024}
}