Sm3+, Tb3+ co-doped NaLa(MoO4)2 temperature sensing materials based on the fluorescence intensity ratio

Sm3+, Tb3+ co-doped NaLa(MoO4)(2) used sodium citrate as chelating agent were coalesced by way of hydrothermal method. In this article, samples exist diverse morphology were obtained by controlling the proportion of sodium citrate in the reaction solution. The microstructure and crystallographic structure of the samples were elaborated through the way of X-ray diffraction (XRD) and Field Emission Scanning Electron Microscope (FE-SEM). Test results indicate that the samples were body-centered tetragonal phase even the proportion of sodium citrate has a measurable influence on morphology. The temperature-dependent emission spectra of Sm3+, Tb3+ co-doped NaLa(MoO4)(2) phosphors were tested with different Cit(3-)/Re3+ at 270 nm fluorescence excitation. It elicits that the fluorescence intensity ratio (FIR) of Sm3+ ion and Tb3+ ion varies with the temperature and can be used to characterize the temperature. In addition, the temperature sensing sensitivity and relative sensitivity increased along with Cit(3-)/Re3+ increases, which the maximum sensing sensitivity is 0.119 K-1 (603 K, Cit(3-)/Re3+ = 2). And the maximum relative sensitivity is 0.0193 K-1 (498 K, Cit(3-)/Re3+ = 2). Simultaneously, from Commission International del'Eclairage (CIE) color coordinates, we can observe that the luminescent color of samples changed obviously with the temperature, so that was used for characterizing the temperature. (C) 2019 Elsevier B.V. All rights reserved.