Colloidal rare earth phosphovanadates for luminescent thermometry

Abstract

The partial dissolution of orthophosphate ions into yttrium orthovanadate lattices led to an enhancement of the luminescence of orthovanadate groups. The combination of the luminescence of vanadate ions with emissions of lanthanide ions can be used to develop self-calibrating optical thermometers with two emitting centers in the same lattice. In this sense, europium(III)-doped yttrium orthovanadate particles containing different amounts of phosphate ions (x=0, 0.05, 0.10, 0.20, 0.30, 0.40 and 1) were prepared by hydrothermal synthesis. The XRD patterns confirmed the formation of solid solutions with tetragonal zircon-type structure. The luminescence analysis showed that composition with 20% of phosphate ions show comparably intense emissions from vanadate groups and europium(III) ions, which is potentially applicable inn ratiometric temperature measurements via two-center downshift luminescence. Additional studies using trivalent thulium and erbium as activators can extend de applicability of the material by enabling dual downshift/upconversion thermometry.