Synthesis of Mn2+:Zn2SiO4–Eu3+:Gd2O3 nanocomposites for highly sensitive optical thermometry through the synergistic luminescence from lanthanide-transition metal ions

Abstract

In this work, Mn²⁺:Zn₂SiO₄–Eu³⁺:Gd₂O₃ nanocomposites were fabricated following a multi-step solution route. The fluorescence intensity ratio of Mn²⁺ to Eu³⁺ in these composites exhibits remarkable temperature dependence, owing to the diverse thermal quenching behaviors of Mn²⁺ and Eu³⁺ ions. Using these nanomaterials to perform thermometry, excellent temperature sensitivity is achieved in the room temperature range. Specifically, the values of relative temperature sensitivity are all beyond 2.5% K⁻¹ in the whole range of 303–323 K (i.e. 30–50 °C), and reach as high as 3.05% K⁻¹ at 303 K, remarkably higher than those of other inorganic optical thermometric materials at a similar temperature. And the absolute sensitivities are all beyond 0.0089 K⁻¹ in this temperature range, which is also a relatively high value. These results indicate the Mn²⁺:Zn₂SiO₄–Eu³⁺:Gd₂O₃ nanocomposites to be very promising nano-thermometric materials.