Synthesis of CaF₂ Nanostructures from Calcium Silicide Powders in Diluted Aqueous HF Solution

Abstract

CaF2 nanostructures were synthesized from Ca-silicide powders by a diluted aqueous HF treatment. Commercially-available CaSi2 crystal powders and calcium silicide powders prepared by mechanical alloying were used as the source materials, and CaF2 nanosheet bundles and nanobunches of the CaF2 nanoparticles were obtained, respectively. The morphological property of the resulting CaF2 nanostructures was characterized by electron microscopy. It was found that the morphology of the resulting products depended on the starting materials. In addition, the growth mechanism of the CaF2 nanostructures was discussed from a topological synthesis point of view.

Synthesis of Mg2Si1−X Ge X solid-solution nanostructures by thermal annealing of CaSi2 crystal powders with Ge and MgCl2/Mg

“…A similar nanobunch structure was reported for CaF 2 nanostructures. 9) The distributions of Si and Ge atoms were examined by chemical mapping of the nanostructure, fabricated at 750 °C for 4 h, and the results are shown in Fig. 2.…”

“…4,5) In addition, several stoichiometric compounds, such as Mg 2 Si, MnSi 1.7 , Mg 2 SiO 4 nanosheet bundles, and CaF 2 nanostructures were synthesized. [6][7][8][9] Furthermore, the crystalline solid-solutions enable variations in stoichiometry of the continuum, which correspond to the variations in structural and physicochemical properties, and offer an opportunity to produce and finely tune the desired properties.…”