The practicality of using nanoparticles in technological applications will depend in part on avoiding costly and time-consuming separation steps and on expanding the range of materials that can be made into nanoparticles to include complex oxides. Hyeon et al. synthesized highly crystalline, monodisperse nanoparticles of maghemite (g-Fe2O3) through the high-temperature aging (300°C) of an iron-oleic acid complex. The particles, whose size could be varied from 4 to 16 nanometers (nm), may find a use in magnetic recording or in ferrofluids. O'Brien et al. synthesized monodisperse nanoparticles of ferroelectric barium titanate (BaTiO3). Particle sizes ranged from 4 to 12 nm, depending on conditions in their sol-gel route. Such particles not only could be used in devices but also could help resolve fundamental mechanistic questions concerning the suppression of ferroelectricity (spontaneous polarizability) in nanoparticles. -- PDS
J. Am. Chem. Soc. 10.1021/ja016812s; J. Am. Chem. Soc. 123, 12085 (2001).
