Synthesis and Characterization of Calcium Hexaboride (CaB6) Nanowires

Abstract

The objective of the current research was to synthesize calcium hexaboride (CaB 6 ) nanowires for analysis of hydrogen storage materials. Catalyst assisted growth of nanowires under the Vapor-Liquid-Solid synthesis method was performed in a quartz tube furnace. The pyrolysis of diborane (B 2 H 6 ) gas over calcium oxide (CaO) powders with a thermally coated layer of nickel catalyst was carried out. SEM and TEM analysis have shown the generation of nanowires although calcium and boron did not react in a 1:6 ratio, though 1:4 and 1:8 ratios were achieved. Several types of nanowire compositions were found under EELS and EDX analyses, including calcium and oxygen coated boron nanowires. Overall, it was found that a decrease in the amount of nickel catalyst used is correlated to a decrease in the diameters of the nanowires. A higher diborane gas flow rate into the reaction chamber was also correlated to more abundant nanostructures in the sample.