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Abstract

In this manuscript we report the production of copper silicate and silicide nanostructures: octahedral o-Cu(SiO3), wire w-Cu(SiO3) and wire w-Cu3Si (embedded in silicate shell) using copper bis(2,2,6,6-tetramethyl-3,5-heptanedionate) [Cu(tmhd)2] precursor and the pulsed injection metal organic chemical vapour deposition (PI-MOCVD) technique. In our experiments, particular attention has been paid to the structural composition and morphological analysis of the nanostructures which are dictated by the deposition parameters such as deposition temperature, carrier gas flow rate and injection time. Deposition processes were diffusion limited and various methods were used to show that by changing the amount of stress relaxation via the reaction time, concentration and flow rate, w-Cu(SiO3) and w-Cu3Si could be made to evolve. Nanostructures have been characterised by x-ray diffraction (XRD), Raman, scanning tunneling electron microscopy (STEM) and atomic force microscopy (AFM) techniques. It was found that the presence of oxygen (SiO2) in the silicon substrates and exposure of the nanostructures to ambient conditions results in the formation of copper silicate from initially produced copper silicide nanomaterials. This work outlines the potential for the manufacturing of various patterned copper nanostructures via PI-MOCVD. 

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