The Temperature Sensing Characteristics of Ba0.60sr0.40tio3 : X%Er3+Powders Based on Upconversion Luminescence

Luminescence thermometers are widely known to provide contactless and the high measurement accuracy. In the paper, the different levels of Er 3+ concentration doped Ba 0.60 Sr 0.40 TiO 3 (BST) powders are prepared by sol-gel method and their structures and the temperature sensing characteristics have been studied. The temperature dependence of the upper quasi-conversion luminescence of Ba 0.60 Sr 0.40 TiO 3 (BST):x%Er 3+ (x=1,2,4,6,8) powders is systematically tested in the temperature range of 303K-543K under 980nm excitation. Benefiting from the special energy levels of rare earth ions, for example, Er 3+ shows different green emission intensity with increasing temperature due to a pair of thermally coupled energy levels 2 H 11/2 and 4 S 3/2 . By measuring the fluorescence intensity ratio (FIR) of the green emission peak of Er 3+ ion, the prepared sample can be used as a probe to measure the ambient temperature of the inserted Er 3+ ion. With the increase of Er 3+ concentration, the sensitivity of Ba 0.60 Sr 0.40 TiO 3 (BST):x%Er 3+ (x=1,2,4,6,8) powders first increased and then decreased, while the maximum sensitivity is obtained at 2% Er 3+ concentration. In addition, the relative sensitivity and absolute sensitivity maximum are 136.18%k -1 at 303K and 16.75%K -1 at 543K, respectively