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 Chi 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 Chi 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 therrnographic 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. (C) 2014 Elsevier B.V. All rights reserved.