High pressure induced disappearing 5D0 → 7F2 and broadening 5D0 → 7F1 transitions from Y2Hf2O7:Eu3+ nanoparticles

Abstract Design of color tunable phosphors as pressure sensors has drawn immense attention. In this work, luminescent Y2Hf2O7:Eu3+ nanoparticles upon high pressure demonstrate lowered phonon frequency, enhanced crystal field, and increased local site swapping effect as manifested with appearing emission of 5D1/5D2 levels, increasing width of magnetic dipole transition (up to ~11.43 GPa), and increased symmetry around Eu3+ ion with disappeared 5D0 → 7F2 transition beyond 5.7 GPa. Our results indicate the potential of the Y2Hf2O7:Eu3+ nanoparticles as medium range pressure sensors with tunable luminescence from red to orange to yellow in the pressure range of 0–49.4 GPa.