The aim of this study was optimization of the annealing process in melt spun Nd2Fe14B intermetallic magnetic alloy. In this regard, the melt spinning process was done at wheel speed of 40 m. s-1. In order to achieving the desired microstructure, the as-spun ribbons were subsequently annealed at temperature range of 500 to 700 º, C for different periods of time. Structural and magnetic characterization of produced samples were performed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The results showed that the structure of as-spun ribbons at wheel speed of 40m. s-1 was composed of Fe-α, , Nd2Fe14B and amorphous phases with the coercivity and saturation of magnetization in the range of 0. 14 kOe and 120 emu/g, respectively. By annealing the produced ribbons and crystallization of the amorphous phase, the percentage of Fe-α,and Nd2Fe14B was decreased and increased, respectively. The optimum annealing conditions for achieving the highest value of coercivity (about 9. 2 kOe) was 600°, C for 6h.

In situ plasma analysis was performed during the single-walled carbon nanotubes (SWNTs) growth from nonmagnetic catalysts with plasma chemical vapor deposition (PCVD). The system based on optical emission spectroscopy (OES) was dedicated for in situ diagnostics of PCVD processes. The SWNTs growth was performed for a various H2 flow rates with 50W of an radio frequency (RF) power. Nonmagnetic metal particles were found to have catalytic activity for the growth of SWNTs under a specific plasma condition. The plasma analysis revealed that the intensities of Ha and CH radicals remarkably increased and decreased by increasing the H2 flow rate, respectively. Based on the comparison between the growth condition of SWNTs and results of plasma analysis, it was found that the intensity ratio of CH/ Ha shows fairly similar tendency to the yield of SWNTs as a function of H2 flow rate, i.e. SWNTs could be grown from nonmagnetic catalysts only when CH/ Ha is high. This indicates that the intensity ratio of CH/ Ha could be useful to optimize the growth condition of SWNTs with Au catalyst.