Growth of Ga2O3 and GaP nanowires synthesized from mixed Ga/GaP powder as a precursor

High-purity gallium oxide (β-Ga2O3) and/or gallium phosphide (GaP) nanowires were synthesized on the nickel or the cobalt oxide catalyzed alumina substrate by a simple chemical vapor deposition method from a mixture of gallium (Ga) and gallium phosphide powder as a source materials. The source materials were directly vaporized in the range of 750–1000 °C for 60 min under argon ambient. The average diameter of nanowires in the optimum synthesis temperature was around 70 nm and the length was up to several hundreds of micrometer. We confirmed that β-Ga2O3 nanowires were observed in all samples, while the GaP nanowires with β-Ga2O3 nanowires were only obtained in the sample synthesized on the nickel oxide catalyst at 950 °C. The β-Ga2O3 and GaP nanowires have a single-crystalline monoclinic and zinc blend structure, respectively. And the both nanowires reveal the core–shell structure, which consists of the β-Ga2O3 or GaP core and the amorphous gallium oxide outer layer.