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

PrLuO 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) and LuO(OH), respectively, into PrO and LuO cubic oxides below 1200 °C, followed by the production of a mixture of hexagonal P6/mmc and orthorhombic Pnma PrLuO phases at 1400 °C. Phase-pure orthorhombic PrLuO 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 PrLuO samples. Dominant emission verified in samples calcined at 1400 °C corresponds to the hypersensitive P → F 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 P → H and P → H transitions with a color purity of 94% (a single luminescence lifetime of 12 μs). The optical properties of PrLuO interlanthanides thereby suggest that they can be used as luminescent materials in both structural arrangements.