Local microstructural analysis for Y₂O₃/Eu³⁺/Mg²⁺ nanorods by Raman and photoluminescence spectra under high pressure

In this paper, we investigate the Raman and photoluminescence spectra of Y₂O₃/Eu³⁺ and Y₂O₃/Eu³⁺/Mg²⁺ nanorods under high pressures using 514-nm and 532-nm laser light excitation. We observe transitions from the initial cubic phase to amorphous at pressures higher than 24 GPa for both Y₂O₃/Eu³⁺ and Y₂O₃/Eu³⁺/Mg²⁺ nanorods. In addition, Y₂O₃/Eu³⁺ and Y₂O₃/Eu³⁺/Mg²⁺ nanorods exhibit different distorted states after the pressure has been raised to 8 GPa. The analyses of intensity ratios, I_0-2/I_0-1 from ⁵D₀-⁷F₂ to ⁵D₀-⁷F₁ and I_0-2A/B of ⁵D₀-⁷F₂ transitions indicate that Y₂O₃/Eu³⁺/Mg²⁺ nanorods exhibit stronger local micro-surrounding characteristics for Eu³⁺ ions in a pressure-modulated crystal field. The doped Mg²⁺ ion results in reducing the crystal ionicity in the distorted lattice state under high pressures. The use of doped ions as an ion modifier can be applied to the study of small local microstructural changes through Eu³⁺ luminescence.