ABSTRACT
Complex materials have unique phonon and electron transport properties. In this chapter, a new manufacturing approach, catalyst-assisted metal organic chemical vapor deposition, was used to make Bi-Te-Ni-Cu-Au complex materials on an anodic aluminum oxide nanoporous substrate. Nickel acetate, copper nitrate, bismuth acetate, and tellurium (IV) chloride dissolved in N,N-dimethylformamide (DMF) were the metal sources for Ni, Bi, Cu, and Te, respectively. Hydrogen was used as the carrier gas. The anodic aluminum oxide substrate was sputter-coated with a gold thin film and was kept at 500°C in a quartz tube reaction chamber. The chemical vapor deposition time was 2 h. Scanning electron microscopic observation was performed to reveal the morphology of the deposited materials. The Bi-Te-Ni-Cu-Au materials showed self-assembled islands. The mechanism for morphology formation was proposed. The nanostructured coating has a higher Seebeck coefficient than most of the bulk materials.
