Simultaneous Enhancement of Up-Conversion Emission and Thermal Sensitivity Via Phase Transition in Gd2(Moo4)3 : Yb3+/Er3+ Crystals

The effects of the site symmetric distortion induced by the phase transition on up-conversion emission and thermal sensing performance of Gd 2 (MoO 4 ) 3 :Yb 3+ /Er 3+ (GMO) crystals are elaborately studied by minimizing interference from many factors. Monoclinic GMO shows much stronger fluorescence intensity and larger fluorescence intensity ratio (FIR) under the irradiation of 980 nm laser compared to orthorhombic counterpart. Such the remarkable up-conversion properties originate from the large site symmetric distortion as its low site symmetry in monoclinic GMO. Moreover, the thermal sensing property of the samples is assessed based on the FIR technique, where monoclinic GMO crystal exhibits much higher maximum absolute sensitivity ( S a = 0.0257 K -1 at 510 K) due to the site symmetric distortion, which was further explained by the Judd-Ofelt theory. Results open an efficient avenue for achieving highly sensitive thermometry in many daily scenario via finely tailoring the local site symmetry