Color-tunable Ca 4-1.5xTa 2O 9: xTb 3+ phosphors are prepared via a convenient solid-state reaction and the cross-relaxation mechanism is investigated. The concentration of Tb 3+ ions greatly affects blue-green emission in Ca 4Ta 2O 9 samples. The cross-relaxation effect is explained with the use of Raman and emission spectra and the thermal stability of Ca 4-1.5xTa 2O 9: xTb 3+ is evaluated under excitation at 254 nm. Using the theoretical fitting results, the cross-relaxation between Tb 3+ ions, via energy transfer from 5D 3 to 5D 4, was determined to be a multipolar interaction of the dipole-dipole mechanism. The critical distance was calculated to be 15.45 Å. The thermal quenching temperature (T 50) is higher than 200°C. Results show that Ca 4-1.5xTa 2O 9: xTb 3+ phosphors have good thermal stability and color tunability.
All Science Journal Classification (ASJC) codes
- Ceramics and Composites
- Materials Chemistry