Opposite temperature luminescent behaviours of Tb3+ and Pr3+ co-doped BaMoO4 glass ceramics for temperature sensing

Tb3+/Pr3+ co-doped transparent glass ceramics (GC) containing BaMoO4 nano-crystalline phase were synthesized and characterized by differential scanning calorimetry, X-ray diffraction, transmittance spectra, and high-resolution transmission electron microscope. The excitation spectra of the sample for the characteristic emission of Tb3+ and Pr3+ ions show a strong broad bands in between 250-300 nm, which are attributed to Pr3+/ Tb3+-Mo6+ charge transfer transitions. Under 266 nm excitation, the luminescent intensities of Tb3+: D-5(4) -> F-7(5) (543 nm) and Pr3+: P-3(1) -> H-3(5) (527 nm) show opposite temperature dependences, as the former decreases due to thermo-quenching while the latter increases due to thermo-coupling of P-3(0) and P-3(1) emissive levels of Pr3+. This leads to a strong temperature dependent luminescent intensity ratio, which is adopted for temperature sensing. Improved relative temperature sensitivity is achieved by making use this novel opposite temperature dependences of two dopants in a single GC sample. The scheme is subject to further optimization in choosing composition and dopants, and promising for application as optical-fiber temperature sensors.

Automated summary

The Tb3+/Pr3+ co-doped transparent glass ceramics were synthesized and characterized, showing opposite temperature dependencies in luminescent intensity which were utilized for temperature sensing with improved relative sensitivity. This innovative approach holds promise for future application as optical-fiber temperature sensors.