Temperature quenching of luminescence emission in Eu3+- and Sm3+-doped YNbO4 powders

We prepared Eu3+- and Sm3+-doped YNbO4 phosphor powders using a simple solid-state reaction method and examined their photoluminescence properties in order to investigate the possibility for their usage in phosphor thermometry. Photoluminescence measurements were performed in the temperature range 303-773 K, and the fluorescence intensity ratio of the paired emissions lines was studied as a function of temperature. The results have shown that YNbO4:Eu3+ possesses the absolute sensitivity of approximately 3×10−3 K−1 at about 700 K, while relative sensitivity changes within the range of 0.5-2.7% K−1. YNbO4:Sm3+ has the maximum sensitivity of around 7×10−4 K−1 at about 700 K with the relative sensitivity of 0.43% K−1 around 500 K. Calculated temperature sensitivities of samples show that these materials have a good potential for the development of thermographic phosphors. Experimental lifetime measurements recorded at 303-773 K were fitted using a temperature dependent charge transfer model, TDCT. This model yields good agreement between experimental and fitted lifetime data. The sample crystalline structure is confirmed by XRD measurements.