Cubic and hexagonal sodium yttrium fluoride were successfully synthesized from yttrium nitrate, sodium fluoride and poly-ethanediol in propanetriol solvent under a facile hydrothermal route. By regulating the molar ratio of yttrium and fluoride, hydrothermal tem-perature and reaction time, the phase and shape of sodium yttrium fluoride were commendably controlled. The as-prepared products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectrum (EDS) techniques. It was revealed that the hollow-structured Na(Y1.5Na0.5)F6 nanotubes self-assembled and arrayed orientedly to be bamboo raft-shaped. The for-mation of hexagonal Na(Y1.5Na0.5)F6 nanotube arrays was attributed to solid-liquid-solid process and Oswald ripening. This study provided a simple method to prepare hexagonal bamboo raft-shaped Na(Y1.5Na0.5)F6 on a large scale, which broadened their practical applications.
Monodisperse sodium yttrium fluoride corn sticks with hexagonal nanostructure were successfully prepared by a facile and repeatable precipitation transformation method.The phase and morphology of the products were characterized with X-ray diffraction(XRD) and scanning electron microscopy(SEM).The growth mechanism was studied,indicating that the initial generated Y(OH)_3gradually translated into YF_3 and then transformed into corn stick-like H-NaYF_4 nanoparticles owing to the crucial role of fluorine ions in the solution.The up-conversion(UC) luminescence properties of H-NaYF_4:20%Yb^(3+),2%Er^(3+) nanocrystals were discussed.The intensive green emission in the range of 510-570 nm was attributed to the(~2H_(11/2),~4S_(3/2))→~4I_(15/2) transition and the weaker red emission between 640 and 680 nm was originating from the ~4F_(9/2)→~4I_(15/2) transition.
