CHAPTER 2: Novel Synthetic Techniques for Nanomaterials

In this work, we describe the use of novel environmentally friendly industrial processing techniques to produce nano-sized crystallite powders and fabricate bulk ceramic pellets of functional materials. We present the application of a microwave (MW)-assisted synthesis process to fabricate the un-doped and doped ceria phases CeO_2−δ, Ce_0.8Gd_0.1Sm_0.1O_1.9, Ce_0.85Gd_0.15O_1.925, Ce_0.85Sm_0.15O_1.925 and Ce_0.8Sm_0.18Ca_0.02O_1.9 for potential application in solid oxide fuel cells. We find that the composition Ce_0.8Sm_0.18Ca_0.02O_1.9 may be most beneficial owing to the highest ionic conductivities encountered in the corresponding sintered ceramics. As a next step, we tested a MW-assisted sintering process to fabricate dense Ce_0.8Sm_0.18Ca_0.02O_1.9 pellets. We find that both the synthesis and sintering process can be achieved by using MW heat sources and the entire fabrication process may be regarded a “green ceramic processing”.