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.
Hexagonal yttrium hydroxide fluoride microcrystals were prepared by a two-step hydrothermal route using yttrium nitrate, sodium hydroxide and sodium fluoride as raw materials to react in propanetriol solvent. The samples were characterized by powder X-ray diffraction (XRD), energy dispersive spectrum (EDS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier trans-form infrared spectroscopy (FT-IR), thermogravimetre and differential-thermogravimetric analysis (TG-DTA), which revealed that Y(OH)2.14F0.86 microcrystals were multi-branched and that the branches of Y(OH)2.14F0.86 microcrystals were composed of hierarchical tubes. This novel multi-branched and intriguing hierarchical tubular structure of yttrium hydroxide fluoride maybe has a potential application in photoelectric crystals. The formation of branched Y(OH)2.14F0.86 microcrystals with hierarchical tubular structure were due to the substitution reaction and Oswald ripening.
