Na(Y_1.5Na_0.5)F₆: RE³⁺ (Dy³⁺,Tb³⁺, Eu³⁺, Tm³⁺, Ho³⁺):Controllable morphology, multicolor light and thermal properties

A series of emission-tunable Na(Y_1.5Na_0.5)F₆: RE³⁺ (Dy³⁺,Tb³⁺, Eu³⁺, Tm³⁺, Ho³⁺) phosphors were firstly synthesized by the glycine assisted one-step hydrothermal process. The structure and morphology were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results revealed that the samples contain YF₃ and Na(Y_1.5Na_0.5)F₆ phases, and the size and shape of the products could be tuned just by adjusting the pH values of the initial reaction solutions or by adjusting the RE³⁺/NaF ratio or RE³⁺/NaBF₄ ratio. The product morphologies include spindle-like microstructures, six prismatic, irregular microrods, micron hexagonal prisms and nano-spheres, micron elliptical disc, flower-like microstructures, spindle-like structures and irregular bulk. Furthermore, the photoluminescence properties of Na(Y_1.5Na_0.5)F₆: RE³⁺ (Dy³⁺, Tb³⁺, Eu³⁺, Tm³⁺, Ho³⁺) were investigated in detail. Additionally, the emission color of Na(Y_1.5Na_0.5)F₆: RE³⁺ (Dy³⁺, Tb³⁺, Eu³⁺, Tm³⁺, Ho³⁺) can be turned by adjusting the amount and kind of RE³⁺ ions. Importantly, the temperature-dependent photoluminescence of as-prepared phosphors was evaluated in detail. All these properties indicate that the developed phosphors may potentially be used as single-component multicolor-emitting phosphors.