Study On Preparation And Photoluminescence Properties Of Novel GdNbTiO₆ Phosphors

Rare earth ions-doped oxide phosphors have been a long focus of research for their better thermal and chemical stability and environmental friendliness.With the development of lighting display areas,to explore new and efficient rare earth luminescent materials caused widespread concern.Titanium niobate compounds have good physical and chemical properties and luminous properties,is a valuable source of luminescent materials,a new type of phosphor research and development of the hot system.In this work,GdNbTiO₆ is served as a host material for phosphors for the first time.Lanthanide ions(Eu³⁺/Dy³⁺)doped GdNbTiO₆ phosphors were prepared by solid-state reaction,with the crystal structure,luminescence properties,and relevant luminescence mechanisms investigated.The crystal structure of Eu³⁺/Dy³⁺ doped GdNbTiO₆ was refined from the powder XRD data by the Rietveld method,which is made up of irregular?Gd/Eu/Dy?³⁺O813-polyhedron and slightly distorted Nb?Ti?O6 octahedron forming an layered structure.The luminescent properties of the GdNbTiO₆:Eu³⁺/Dy³⁺ phosphors were studied under ultraviolet?UV?and vacuum ultraviolet?VUV?excitation.The GdNbTiO₆ host shows a broad emission band about 380-650 nm regions centered at 509 nm owing to the Nb?Ti?O6 octahedral groups,which has spectral overlaps with excitation of f-f transitions of Eu³⁺/Dy³⁺ in doped samples.For red phosphors GdNbTiO₆:Eu³⁺,dominant emission peaking at 614 nm was attributed to 5D0?7F2 transition of Eu³⁺,which confirmed that Eu³⁺ ions are located at sites without inversion symmetry.The phosphors GdNbTiO₆:Dy³⁺ shows bright yellow-green emission prevailing at 577 nm with 273 nm excited.With increasing activators concentrations,the emission derived from the characteristic f-f transitions of Eu³⁺/Dy³⁺ has been enhanced while the host emission has weakened,which owns to the energy transfer from the host to Eu³⁺/Dy³⁺.Considering the facile synthesis and excellent Eu³⁺/Dy³⁺ doped luminescent properties of this compound,self-activated GdNbTiO₆ may be a good candidate as host of phosphors using in various optical devices.Niobate GdNbTiO₆,YNbTiO₆ and CaNb₂O₆ phosphors were nitrided,that is,the anion N-doping was carried out,and the excitation spectra and emission spectra of all samples of nitrided and non-nitrided in the ultraviolet region were measured.The treatment can effectively improve the luminous intensity of niobate.The results show that the addition of sensitizers Li³⁺ and Al³⁺ is beneficial to the performance of red phosphors GdNbTiO₆:Eu³⁺,and can also replace the gadolinium ions in part to achieve cost savings.GdNbTiO₆ phosphor is easy to synthesize and excellent RE³⁺ doped luminescent properties.Self-activated GdNbTiO₆ can be used as a good candidate phosphor matrix for use in various optical devices.