% cobalt acetate. The precursors were rapidly heated to 310°C in an electric furnace with an inert gas atmosphere for fast thermal decomposition (Figure 1). The syntheses were carried out using different ambient gases, including flowing inert Ar (99.999%), flowing air (99.999%) with a continuous oxygen supply, and closed air Birinapant cell line (99.999%) with oxygen inclusion only for the initial reaction (Table 1). The gas flow rate was maintained at 25 sccm. The nanowire length was manipulated from 500 nm to 3 μm by controlling the synthesis time between 30 min and 2 h. The synthesized nanowires were cleaned in ethanol and distilled water repeatedly, followed by annealing

in stages at 300°C for 10 h and 800°C Dasatinib for 10 h under a vacuum (10-2 Torr) to remove organic residues. For comparison, ZnCoO nanopowder [13] and ZnCoO micropowder [20] were also prepared (see the

references for detailed information). Hydrogen injection was performed by plasma treatment using an Ar/H (8:2) mixed gas (99.999%), and all samples were exposed twice for 15 min to hydrogen plasma using an RF power of 80 W. Figure 1 Electric furnace for the synthesis of ZnCoO nanowires. Table 1 Controlling ambient gas by gas distinction Sample name Gas S1 Argon gas (99.999%, continuous flow) S2 Air gas (99.999%, continuous flow) S3 Air gas (99.999%, non-continuous) The change in nanowire morphology and the secondary phase were investigated by field-emission scanning electron microscopy (FE-SEM, S-4700, Hitachi, Tokyo, Japan) and X-ray diffraction (XRD, Empyrean series2, PANalytical, Almelo, The Netherlands). Magnetic properties such as magnetization were measured using a vibrating sample magnetometer (VSM, model 6000, Quantum Design, San Diego, CA, USA) attached to a physical property measurement system. Results and discussion Figure 2 shows the FE-SEM images of the ZnCoO nanowires synthesized using different ambient gases. Figure 2a shows the FE-SEM images of the samples labeled S1, which were fabricated using ambient Ar gas.

Figure 2b shows the same image magnified by a factor of three. ZnCoO nanowires were produced sporadically, and the average length was 700 nm. Figure GBA3 2c shows the FE-SEM images of the samples labeled S2, which were fabricated using air continuously supplied with oxygen. Figure 2d shows the same image magnified by a factor of three. ZnCoO nanowires were produced sporadically, and the maximum length was approximately 2.5 μm. Figure 2e shows the FE-SEM images of the samples labeled S3, which were generated using a fixed air supply with restricted oxygen content. Figure 2f shows the same image magnified by 1.5. The ZnCoO nanowires were produced uniformly, and the average length was 2 μm. These results indicate that the morphology of the ZnCoO nanowires depends on the ambient gas and, in particular, on the oxygen content.