Nanodesigning of Multifunctional Ceramic Composites,

There has been a growing interest in the colloidal processing of nanocomposites because of the advantages or using nanometer-sized particles.1-3 For example, it is possible to mix different components on a nanometer scale and achieve improved electronic and structural properties for multifunctional applications. 3 -5 Another advantage is that the materials can be processed to full density at much lower temperatures than by conventional methods. Previous literature has discussed some of the advantages and difficulties in colloidal processing with nanometer-sized particles compared to the processing of micrometer and submicrometer-sized particles.1 .2 The most significant difficulty is that nanometer-sized particles in general result in the formation of low-density gels which display large shrinkages during solvent extraction and, therefore, cracking during drying or sintering.6,7 In this paper, we discuss this problem from a more fundamental point of view and summarize our recent work in this area. We then extend our discussion to binary systems, which have not been understood as well. The study and understanding of multicomponent systems is essential for processing composite materials with two or more components. Through such an understanding, high-packing density can be realized, and also the distribution of species can be controlled so that regularity in the structure and the scale of homogeneity in composition can be predicted.