Abstract

Spinel oxides have been one of the most important oxides in material science. In the form of ceramics, spinels have applications such as gas sensors, pigment materials, phosphors, catalysts, battery electrodes, infrared windows, and transparent electric conductors. However, ceramics are made up of highly compressed grain particles whose sizes range from nano- to micrometers. With nanotechnology, it is possible to make nanoparticles with more uniform sizes and finer grain structures. If traditional ceramic spinels are substituted with such nanostructured spinel nanoparticles, it is expected that some of the application performance can be enhanced. Driven by this, the preparation and characterization of nanoscale spinel oxides, in the form of nanoparticles, nanotubes, and nanowires (dimensions below 100 nm), have been recently receiving much attention (Song and Zhang 2004, Zeng et al. 2004a,b, Wang et al. 2005: 2928, Tirosh et al. 2006). Because of a large surface-to-volume ratio and symmetry breaking on the surface, nanoscale spinel oxides have shown physical properties different from their bulk counterparts. This chapter discusses only quasi one-dimensional (1D) nanostructures (e.g., tubes and wires).