Formation of YF3 Nanocrystals and Their Self-Assembly into Hollow Peanut-Like Structures

A simple hydrothermal route has been used to prepare hollow peanut-like structures of orthorhombic YF 3 by using a suitable tetrafluroborate complex as the fluoride source. The as-synthesized products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Four tetrafluroborate complexes NaBF 4, NH 4 BF 4, KBF 4, and HBF 4 were examined in this synthetic procedure. YF 3 nanocrystals formed from NaBF 4, NH 4 BF 4, or KBF 4 were found to self-assemble into hollow peanut-like structures. Time-dependent studies of the reactions have been conducted to reveal the morphological evolution, and the possible mechanistic pathways in the formation of the hollow structures are proposed.