Thermal, vibrational and optical properties of PrLuO₃ interlanthanides from hydrothermally-derived precursors

PrLuO₃ interlanthanides were prepared at temperatures ranging from 800 °C to 1600 °C using hydrothermally-derived precursors. The chemical reactions observed include the conversion and segregation of Pr(OH)₃ and LuO(OH), respectively, into PrO₂ and Lu₂O₃ cubic oxides below 1200 °C, followed by the production of a mixture of hexagonal P6₃/mmc and orthorhombic Pnma PrLuO₃ phases at 1400 °C. Phase-pure orthorhombic PrLuO₃ was obtained at 1600 °C, which was corroborated by Raman and micro far-infrared spectroscopic analyses. Photoluminescence, colorimetric and lifetime measurements were carried out in PrLuO₃ samples. Dominant emission verified in samples calcined at 1400 °C corresponds to the hypersensitive ³P₀ → ³F₂ transition with a color purity of 97% (decay times of 12 μs and 3 μs), while emissions for the phase-pure samples correspond to the ³P₀ → ³H₆ and ³P₀ → ³H₅ transitions with a color purity of 94% (a single luminescence lifetime of 12 μs). The optical properties of PrLuO₃ interlanthanides thereby suggest that they can be used as luminescent materials in both structural arrangements.