The Effect of Starting Precursors on Size and Shape Modification of ZrB2 Ceramic Nanoparticles

The formation of ZrB2 nanoparticles through reaction of Zr(n-PrO)4 with H3BO3 and carbon has been studied with different ligands by carbothermal reduction at 1500 degrees C. In the first step, by introducing N, N'-bis (salicylidene)-1,3-diaminopropane (H2salpn) or salicylaldehyde (Hsal) species into reaction mixture, the reaction of the zirconium alkoxide using citric acid and boric acid yielded the zirconium diboride (ZrB2) sol-gel precursors. In the second step, the mixture was heated by introducing the reactant compact into an argon furnace held at 1500 degrees C for 2 h to obtain the final pure phase ZrB2 nanocrystallites with a diameter of about 50 nm. The kind of chelating agent used in the preparation of ZrB2 nanoparticles plays the predominant role on the final product size. This demonstrates that the proper kind of donor atom and a very specific ligand structure are necessary for the reaction of Zr4+ complexes.