ABSTRACT
Miniaturization has become a standard trend in many current technologies, whether it be for light weight or space saving applica-tions, minimizing the amount of materials used, or to increase, for example, device efficiency. Paralleling this trend, are considerable efforts to understand the properties and performances of materials in the size range of a few nanometers. In the particular case of oxides, particles in this size range can consist of just a few unit cells. Most oxide nanoparticles develop new or enhanced properties that bring about new studies and discoveries.This chapter focuses on oxide and bioceramic nanoparticles, mainly obtained by the sol-gel technique. The importance of oxide and biocompatible nanomaterials relies on their chemical stability, low cost, multifunctionality, general inertness, and the potential for radiolabeling and tracer applications. Our emphasis
on the sol-gel technique relates to its versatility in terms of starting materials, solvents, and additives, and on its potential to homogenously mix the constituents at the molecular level, thus allowing for the accurate control of the final composition and stoichiometry. Furthermore, both the organic moieties present and the low temperatures required to crystallize the desired phase, lead to the formation of very fine particles of diameters in the range of a few tens of nanometers. Carbide and nitride ceramic materials are not covered in this chapter; comprehensive information about these fascinating materials can be found, for example, in references [1-3].
