Luminescence properties of Sm3+ doped YPO4: Effect of solvent, heat-treatment, Ca2+/W6+-co-doping and its hyperthermia application

Abstract

Sm3+ doped YPO4 spherical nanoparticles are prepared by wet chemical route. Pure YPO4 shows the tetragonal phase, which is stable up to 900 °C, whereas pure SmPO4 shows the phase transition from hexagonal to monoclinic when heated above 800 °C. The (2-10 at.%) Sm3+ doped YPO4 shows the mixture of phases of tetragonal and hexagonal, which transform to the tetragonal phase above 800 °C. Infra-red study could distinguish confined water in the pore of hexagonal phase from water present on the surface of particles. Luminescence intensities of Sm3+ at 564, 601 and 645 nm are weak in case of as-prepared samples because of high non-radiative rate arising from the H2O molecules present in pores of hexagonal lattice. The intensities increase for samples heated up to 900 °C because of increase of extent of radiative rate. Luminescence lifetime increases with increase of heat-treatment up to 900 °C. When solvent of as-prepared sample was changed from the H2O to D2O, 5 times enhancement in luminescence intensity is observed, which can be ascribed to the lower vibration energy of D-O over H-O, which is near to Sm3+. When Y3+ and P5+ ions are substituted by Ca3+ and W3+ up to 3 at.%, there is an enhancement of luminescence. In order to use them as bio-labeling in drug delivery for hyperthermia applications, hybrid of Fe3O4@YPO4:7Sm is prepared and heating up to 45 °C is observed under AC magnetic field.

Fabrication of Spherical Magneto-Luminescent Hybrid MnFe2O4@YPO4:5 Eu3+Nanoparticles for Hyperthermia Application

“…Figure (a) represents the TGA‐DTA curves of YPO 4 NPs prepared in ethylene glycol medium. There are two steps of weight loss in TGA curve, one below 300 °C due to loss of surface water and another below 500 °C due to the loss of bound water present in the prepared NPs . There is also an exothermic peak at around 279 nm due to the decomposition of ethylene glycol.…”

Phase composition and morphology of nanoparticles of yttrium orthophosphates synthesized by microwave-hydrothermal treatment: The influence of synthetic conditions

“…Chemically and thermally stable, highly crystalline, photostable and efficiently emitting, these particles are admitted to be an attractive candidate for a wide range of applications, from optoelectronics (display and LED production) to biomedicine. The biomedical application include such areas as cell labeling [1], the detection of molecules [2], while YPO 4 containing composite nanoparticles were suggested for hyperthermia treatment [3]. Apart from high fluorescence intensity and stability, the latter impose additional requirements on the material properties, namely, low toxicity, high biocompatibility and dispersability in aqueous media.…”

An energy transfer kinetic probe for OH-quenchers in the Nd3+:YPO4nanocrystals suitable for imaging in the biological tissue transparency window

“…Therefore one of the main problems for the NPs development for bioimaging is protection of NPs against the inner and surface water. Fluorescence quenching is enhanced further by placing nanoparticles in aqueous environment, which is a necessary stage of cancer diagnostics, as well as any other medical treatment 15 . Moreover, the concentration of nanoparticles in colloidal solution during in vivo experiments should be as low as possible to avoid or at least minimize intoxication.…”