Published online by Cambridge University Press: 31 January 2011
Nickel ferrite nanostructured particles coated with chemisorbed oleic acid were successfully synthesized by nonhydrolytic sol-gel method. By varying the composition of metal precursors, two microstructures were obtained, i.e., dispersed nanocrystals (9.7 ± 1.8 nm) and submicron aggregates (152 ± 21 nm) consisted of many nanocrystals (8.1 ± 1.3 nm). Because oleic acid could form complex with iron (III) ions, but not with nickel (II), increasing the concentration of iron precursor consumed more oleic acid and led to insufficient oleic acid coating on particle surface. Strong intercrystallite interaction was induced from less protected nanocrystals, and aggregation thus occurred between different crystallites.