Temperature sensing and magnetic properties of the Fe3O4@ZrOBDC:Eu3+,Tb3+ MMOF

In this paper, we present the method for synthesizing multifunctional core/shell Fe 3 O 4 @ZrO-BDC:Eu 3+ ,Tb 3+ magnetic metal−organic frameworks (MMOF) through a hydrothermal route. In this approach, magnetic Fe 3 O 4 nanoparticles are used as a core for growing the shell of ZrOBDC:Eu 3+ ,Tb 3+ nanoscale metal-organic frameworks (NMOF). The formation of the core/shell Fe 3 O 4 @ZrOBDC:Eu 3+ ,Tb 3+ MMOF with an average size of 10–25 nm was confirmed by FESEM, TEM imaging, and XRD analysis. The process of forming the ZrOBDC:Eu 3+ ,Tb 3+ NMOF shell layers was also investigated using FT-IR techniques. The temperature dependence of the emission intensity of the core/shell Fe 3 O 4 @ZrOBDC:Eu 3+ ,Tb 3+ MMOF was studied in the 153–573 K temperature range. The obtained results demonstrated that the luminescence intensities ratios of 5 D 4 → 7 F 5 (Tb 3+ ) to the 5 D 0 → 7 F 2 (Eu 3+ ) bands can be used for ratiometric temperature sensing with the maximum sensitivity of ∼0.73%K −1 . Moreover, the increase in temperature results in a change of the emission colour from green to yellowish. Furthermore, vibrating sample magnetometer measurements indicate the ferromagnetic behavior of the core/shell Fe 3 O 4 @ZrOBDC:Eu 3+ ,Tb 3+ MMOF in the temperature range from 100 to 300 K, with a saturation magnetization values of 25.08; 23.04 and 20.57 emu/g and the corresponding coercive forces (Hc) are 20.61; 27.63 and 54.35 Oe, respectively. • A new method for synthesized of core/shell Fe 3 O 4 @Zr-MOF:Eu 3+ , Tb 3+ is presented. • Tb 3+ luminescence was thermally quenched more efficiently comparing to Eu 3+ . • Tb 3+ to Eu 3+ luminescence was used as a temperature sensor. • Increase of temperature affects emission color of the material. • The ferromagnetic properties of the material was investigated.