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- Title
The synthesis of hafnium nanomaterials by alkali metal reduction of hafnium tetrachloride.
- Authors
Purdy, Andrew; Sorber, Rebecca; Epshteyn, Albert; Pettigrew, Katherine; Miller, Joel
- Abstract
Hafnium tetrachloride was reduced in organic solvents with lithium powder, sodium-potassium alloy, or lithium hydride/EtB. All reductions required sonochemical agitation to proceed at an appreciable rate, with the notable exception of the reaction of HfCl with Li in diethyl ether. Activation of C-H bonds occurred in all reactions, which resulted in carbon-containing products. HfCl was reduced on a 50-g scale with LiH/EtB, and a 10-g scale with Li powder in pentane. All the solid products from the reductions were converted to nanomaterials by annealing under vacuum from 500 to 1,000 °C, which also resulted in the sublimation of the alkali metal salts. The nanomaterials contain a mixture of products with the α-Hf (hexagonal) structure (crystallite size 8-250 nm) and the HfC (FCC) structure (crystallite size 3-80 nm), with the amount of hafnium in the bulk annealed product varying from 88 to 99 wt%. When toluene, pentane, or triethylamine solvents were used, the presence of amorphous graphitic or carbonaceous material was also detected by solid state C NMR. Thermally annealed products were additionally characterized by electron microscopy and thermal analysis under Ar/O, and have BET surface areas ranging from 2.7 to 155 m/g.
- Subjects
INORGANIC synthesis; HAFNIUM; NANOSTRUCTURED materials; ALKALI metals; CHEMICAL reduction; HAFNIUM tetrachloride; SODIUM alloys; CHEMICAL bonds; METAL powders; ANNEALING of crystals
- Publication
Journal of Nanoparticle Research, 2011, Vol 13, Issue 10, p5435
- ISSN
1388-0764
- Publication type
Article
- DOI
10.1007/s11051-011-0531-8