| Summary: | 碩士 === 國立臺灣科技大學 === 機械工程系 === 106 === In this study, heterostructure Cu0.55Ge0.45 nanowires were fabricated by vacuum hydraulic pressure injection molding with anodic aluminum oxides (AAOs) template. First, in order to establish a mirror-like surface, high purity aluminum sheets (99.999%) were electropolished in the solution composed of perchloric acid (15%) - ethanol (70%) - monobutylether ethanol (HOCH2CH2OC4H9) (15%) at 40 V for 30 minutes. The electropolished specimens were anodized in oxalic acid at 50 V for two days, and then AAOs with nanopore array having a diameter of 90 nm were obtained. In the second step, via vacuum injection molding process, Cu0.55Ge0.45 hypereutectic alloy was heated to 750 °C and filled into AAO template. After removing AAO in etching solution, Cu0.55Ge0.45 nanowires with diameter of 90 nm were hence obtained. Based on OM and XRD results, the crystal structure of Cu0.55Ge0.45 bulk material is determined as Ge/Cu3Ge coexisting phases. Next, comparing Cu0.55Ge0.45 nanowires before and after annealing treatments, SEM and EDS results show that Ge and Cu elements tend to form Ge and Cu-Ge segments. TEM was further used to confirm two different segments of the nanowires are Cu3Ge and Ge, respectively. It was proved that vacuum injection molding process can be used to successfully multiple the original bulk material to nanowires, in which each segment is of single crystalline structure. It was found that the Ge segment of annealed nanowires had less copper content; thus, annealed Cu0.55Ge0.45 nanowires are closer to metal/semiconductor heterostructure.
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