Rare earth β-NaGdF(4) fluorides with multiform morphologies: Hydrothermal synthesis and luminescent properties

In this paper, the synthesis of rare earth fluoride β-NaGdF(4) with multiform morphologies via a facile hydrothermal method has been fulfilled. The phases and shapes of the products can be tuned by changing the experimental parameters, including F(-) source and pH value of mother liquor. The morphologies for the products range from submicrorods, submicrospheres, dumbbell-like nanorods, cobblestone-like particles to aggregates constructed from nanoparticles. The results indicate that F(-) source and pH value play a critical role in determining the morphologies of the final products. Additionally, we investigate the photoluminescence (PL) properties of Ce(3+)/Ln(3+) (LnEu, Tb and Dy) codoped down-conversion (DC) and Yb(3+)/Er(3+) (Tm(3+), Ho(3+)) codoped up-conversion (UC) in β-NaGdF(4) host lattices. In the process of DC photoluminescence, energy transfer has occurred. This energy transfer occurs through the energy migration process like S→Gd(3+)→(Gd(3+))(n)→A (S represents the sensitizer and A represents the activator) and the Gd(3+) plays an intermediate role in the process.