Abstract The Y2Ti2O7: Er3+/Yb3+ phosphors co-doped with Li+ and Li+/Mg2+ ions were prepared via solid state reaction method. The effects of Li+ and Mg2+ co-doping on the structure and morphology of Y2Ti2O7: Er3+/Yb3+ phosphors were investigated by X-ray diffraction (XRD), electron paramagnetic resonance (EPR) spectra and field emission scanning electron microscopy (FESEM) observations. The 980 nm excitation assisted UC luminescence intensity for green and red band was enhanced by 8.7 and 14.3 times respectively after co-doping with Li+/Mg2+ ions in Y2Ti2O7: Er3+/Yb3+, which could be explained based on the variations in crystal structure and particle size. Using the fluorescence intensity ratio (FIR) technique, the impact of 980 nm pump power on the thermometric behaviors was studied based on the thermally coupled levels of 2H11/2 and 4S3/2 of Er3+ ions. Due to the unique thermal properties of the Y2Ti2O7 host, the temperature increment caused by laser thermal effect was minimized, benefiting the consistency of FIR data over a wide range of pump power density. Besides, a high relative sensor sensitivity of 1.17%K−1 was obtained for Y2Ti2O7: Er3+/Yb3+/Li+/Mg2+ phosphors. These characteristics may make the studied system applicable for optical temperature sensor with high accuracy.

中文翻译：

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Li+/Mg2+ 共掺杂对 Y2Ti2O7: Er3+/Yb3+ 上转换磷光体中光学温度传感行为的影响

摘要 采用固相反应法制备了Li+和Li+/Mg2+共掺杂的Y2Ti2O7:Er3+/Yb3+荧光粉。通过 X 射线衍射 (XRD)、电子顺磁共振 (EPR) 光谱和场发射扫描电子显微镜 (FESEM) 观察研究了 Li+ 和 Mg2+ 共掺杂对 Y2Ti2O7: Er3+/Yb3+ 荧光粉结构和形貌的影响。在Y2Ti2O7：Er3+/Yb3+中与Li+/Mg2+离子共掺杂后，980 nm激发辅助UC绿带和红带发光强度分别增强了8.7和14.3倍，这可以根据晶体结构和颗粒的变化来解释尺寸。使用荧光强度比（FIR）技术，基于 Er3+ 离子的 2H11/2 和 4S3/2 的热耦合水平，研究了 980 nm 泵浦功率对测温行为的影响。由于 Y2Ti2O7 主体独特的热性能，激光热效应引起的温度增量被最小化，有利于 FIR 数据在很宽的泵浦功率密度范围内保持一致性。此外，Y2Ti2O7: Er3+/Yb3+/Li+/Mg2+ 荧光粉获得了 1.17%K-1 的高相对传感器灵敏度。这些特性可以使所研究的系统适用于高精度的光学温度传感器。Y2Ti2O7：Er3+/Yb3+/Li+/Mg2+ 磷光体获得17%K-1。这些特性可以使所研究的系统适用于高精度的光学温度传感器。Y2Ti2O7：Er3+/Yb3+/Li+/Mg2+ 磷光体获得17%K-1。这些特性可以使所研究的系统适用于高精度的光学温度传感器。