Abstract
The theme of this dissertation mainly focuses on following nano-materials: (1) silicide, (2) silicon, and (3) metal oxide. Basically, they possess two different kinds of properties, namely, metallic and semiconducting properties, which can be applied in various applications. For silicide materials, we try to synthesize the semiconducting feature of β-FeSi2 thin film/nanodots on Si and SiGe virtual substrates for application at light emitting device and discuss on how the effect of morphologies and dimensionality for these nanodots can influence their optical properties. In addition, by in-situ annealing FeSi2 nanodots grown on Si and SiGe alloy virtual substrates, the taper- and rod-like Si nanowires are successfully synthesized. The possible growth mechanisms are discussed in detail based on the SLS and OAG for taper-like SiNWs and VLS for rod-like SiNWs.Furthermore, metal silicides have many interesting properties, such as high melting temperature, superb thermal stability and low resistivity. In this thesis, we utilized an innovative method to synthesize the metallic TaSi2 nanowires by annealing FeSi2 and NiSi2 films and nanodots on Si substrate in an ambient containing Ta vapor at a pressure lower than 1×10-6 Torr. The growth mechanisms are illustrated and the electrical, mechanical, magnetic, field-emission properties are measured as well.For the metal oxide nanomaterials, we focus on synthesis of various functional metal oxide nanomaterials as follows: (1) SiO2/Ta2O5 core-shell and Ta2O5 nanotube as well as nanowires, (2) Fe2O3 and Fe3O4 NW, (3) RuO2 and RuO2/TiO2 core-shell NW, (3) The Zn3P2 and ZnO NW for various applications. The studies for these functional metal oxide nanomaterials mainly focus on synthesis, microstrucutre characterizations, and functional measurements, including optical, mechanical, magnetic, and field-emission properties. Device fabrications and testing for these nanomaterials are carried out as well. The results show the great potential of these nanomaterials in future applications.