Altering of the Electric and Magnetic Dipole Transition Probability of Eu3+ in YPO4 Lattice by Codoping of K+ Ion: Potential Materials for Imaging and Heating

Aqueous, dispersible, luminescent YPO 4:Eu 3+ -K + and hybrid magnetic-luminescent Fe 3 O 4 @YPO 4:Eu 3+ -K + nanoparticles are prepared at an optimum temperature with a simple synthesis route. The shape of YPO 4:Eu 3+ -K + nanoparticles is found to be nanorods. Photoluminescence spectrum of a sample upon excitation at 395 nm shows the characteristic peaks of Eu 3+ such as magnetic–dipole transition ( 5 D 0 → 7 F 1 ) at 592 nm, the electric–dipole transition ( 5 D 0 → 7 F 2 ) at 615 nm, and electric–dipole transition ( 5 D 0 → 7 F 4 ) at 695 nm. Luminescence intensity increases with K + doping. Interestingly, their luminescence intensities are almost the same. This could be explained by the polarizability effect of the PO 4 3– group and K + upon emission of Eu 3+ . This high intensity at 695 nm will be useful in bioimaging since this wavelength falls in biological window I. This hybrid material shows a hyperthermia temperature under an AC magnetic field, making this material a potential candidate for cancer therapy.