Fig. 2: Lattice vibration of CIPS.
From: Anomalous polarization enhancement in a van der Waals ferroelectric material under pressure
a Pressure-dependent Raman spectra of CIPS from 0 to 1.90 GPa. b Pressure-evolution of the logarithms of the relative intensity ratio of the modes at 72, 104, 116, 162, 264, and 315 cm−1. c Relative Raman shifts of the modes at 72, 104, 216, 238, 264, and 315 cm−1 under pressure. d The schematic diagram of the Raman modes for cation, anion (P2S64-), S-P-P, S-P-S vibrations, P-P stretching, and P-S oscillations. e The schematic diagram of the evolution of Cu cations below 0.26 GPa.
