High-Pressure Behavior of NdF₃: Structural and Photoluminescence Properties

Abstract This paper investigates the pressure-induced photoluminescence properties and structural phase transitions of functional material NdF3 at room temperature using diamond anvil cell (DAC), in-situ photoluminescence technology, and simulation calculations. Under hydrostatic experimental pressure and simulated pressure up to 20 GPa, the photoluminescence spectra, lattice parameters, and bond lengths of NdF 3 were obtained, showing their variations with pressure. Experimental results show that a new emission line, corresponding to the 4 F 3/2 → 4 I 9/2 transition of Nd 3+ ions, appears around 12 GPa and persists up to the highest pressure of the experiment. Upon decompression, the new emission line disappears, indicating a reversible phase transition. Notably, from 0 to 12 GPa, the emission intensity of NdF3 decreases significantly under pressure, which may be attributed to the increased energy of lattice phonons in the compressed crystal (shorter Nd-F bonds), leading to enhanced phonon-assisted non-radiative relaxation.