Abstracts

With the increasing demand for more precise and small-scale temperature sensors, lanthanide ion-based compounds have gained prominence due to their high dependence of luminescence on temperature. These compounds offer the potential for miniaturization of temperature measurement tools, down to the nanoscale, enabling precise temperature measurement even in cellular environments. Notable applications include industrial systems and electronic circuit boards. An accurate method for evaluating temperature via luminescence involves using the ratio between two emissions of different levels in a ratiometric system. This method eliminates errors associated with electrical fluctuations, background noise, and sample concentration. Luminescent complexes based on lanthanide ions coordinated to organic ligands and inserted into a polymeric matrix are promising for several applications. In this study, the complex [Eu(tta)₃(PIB)] was used as a luminescent component in a castor oil-based film prepared via the Sol-Gel route, at 0.25% complex concentration. The complex before and after incorporation into the film was monitored via FTIR, and the successful synthesis of the complex was verified by detecting Eu-O and Eu-N stretches, between 400 cm^-1 and 600 cm^-1, as well as the absence of band at 2,250 cm^-1 (n_NCO) in the film, indicating polymer formation. Furthermore, the luminescence behavior before and after film formation was studied via photoluminescence spectroscopy (PLS). Furthermore, the luminescent film had its thermometric performance evaluated in the range between 13 K and 325 K. The developed system exhibited an ideal working window between temperatures of 125 K and 282 K, achieving a maximum relative thermal sensitivity (S_m) of 1.8% K^-1 at 270 K, with a minimum temperature uncertainty (dT) of 5 K at 225 K. The values obtained are considered suitable for further in-depth investigations regarding application in luminescent thermometry.