Innovative core-shell Au/Ga2O3 nanowires were synthesized by the reaction of metal gallium powders, silica substrates, and gold nanoparticles at 800 ℃ under a pressure of 10-2 Torr via VLS growth mechanism. Controllable diameters of the nanowires were achieved by using the variously commercial gold nanoparticles dispersed on silica substrates. The crystal structure, microstructure, chemical composition, and optical properties of the as-grown products were examined by X-ray diffractometer (XRD), transmission electron microscope (TEM), scanning transmission electron microscope (STEM), and cathodoluminescence (CL) spectrometer, respectively. In addition, the symmetric twin boundary induced by the larger Au catalyst was found at the center of the nanowire, which plays an important role during the initial formation of the core-shell nanowires.
Based on the localized surface plasmon resonance (LSPR) effects, the investigation of optical scattering spectrum caused by embedded Au nanoparticles or nanowires with different sizes and shapes in Ga2O3 matrix was carried out. The red and blue shifts of transverse resonance peaks were measured with the increase of diameters and aspect ratios, respectively. This one-step synthesis of core-shell Au/Ga2O3 nanowires provides a potential way to produce the future functional nanodevices.

Chapter 1
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