Two ratiometric thermometry methods based on the interplay between Eu[formula omitted] and Eu[formula omitted] and single Eu[formula omitted] emissions on OH[formula omitted]-free low-silica calcium aluminosilicate glass

Abstract

The constant demand to accurately measure the temperature sheds light on luminescent materials that have dependence on their thermodynamic quantities. Several materials have been applied as sensors to measure temperature for different applications, however, very few showed high precision and sensitivity. This work reports the Eu2+/Eu3+-doped low-silica calcium aluminosilicate glass as a potential candidate for high sensitive ratiometric thermometer. The glass was analyzed close to the physiological temperature range, between 288.15 – 333.15 K. Since this glassy matrix provides the presence of two europium valences, two different approaches are presented. The first takes into account the temperature dependence of 5D0→7F4 emission for two different excitation wavelengths, and the second one is based on the interplay between Eu2+ and Eu3+ emissions. Both ratiometric approaches presented high reproducibility and relative sensitivity values, from 1.2 to 1.6 %/K and from 0.75 to 0.95 %/K, for the first and second approach, respectively.