Lattice and Electronic Structural Evolutions in Compressed Multilayer MnPS₃

Abstract

MnPS 3 , a novel ternary-layered material, has attracted extensive attention in materials, physics, and chemistry owing to its excellent electrical transport and photoelectric properties. Pressure is a useful technique to explore unprecedented phenomena and properties in condensed matter. In this study, combining high-pressure Raman spectroscopy, high-pressure absorption spectroscopy measurements, and first-principles calculations, the pressure-induced lattice and electronic structural evolutions of multilayer MnPS 3 were uncovered. A pressureinduced lifted symmetry (layer sliding) of multilayer MnPS 3 from the C2/m-staggered P-dimer phase (phase I) to P3̅ 1m aligned Pdimer phase (phase II) at 6.7 GPa was demonstrated, evidenced by the overlap of E g 5 and A 1g 3 modes under high pressure and further first-principles calculations. Meanwhile, the linearly decreased optical band gap with pressure indicated that the chargetransfer excitations that define the gap were confined in intra-slab in nature regardless of the interlayer sliding. Further calculated band gap structure also suggested that no obvious electronic structural phase transition occurred in multilayer MnPS 3 during the pressure-induced phase transition of multilayer MnPS 3 except from a decreased band gap with pressure. In addition, both the results of absorption spectroscopy measurements and first-principles calculation demonstrated that multilayer MnPS 3 remained to be a direct band gap semiconductor up to 21.8 GPa. Our findings are of great significance in expanding the application of compressive MnPS 3 in photoelectric devices.

MPX3 van der Waals magnets under pressure (M = Mn, Ni, V, Fe, Co, Cd; X = S, Se)

“…We note in passing that theory tends to over-estimate the band gap and pressure of the insulator-to-metal transition in these materials (Grasso et al, 1991;Harms et al, 2020;Yan et al, 2023). Gap estimation is a well-known challenge for first-principles density functional theory-based approaches, and weak interactions with shallow potentials are notoriously difficult to calculate with accuracy.…”

“…From the optical properties point of view, MnPS 3 is a semiconductor with a 2.7 eV band gap. It hosts spin-charge coupling across the magnetic ordering transition and a set of crystal field excitations that have been widely investigated (Boerio-Goates et al, 1981;Grasso et al, 1991;Harms et al, 2020;Yan et al, 2023;Park et al, 2024). There is strong p-d hybridization which activates the d-to-d on-site excitations of the Mn 2+ centers.…”