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We have studied the electronic structure and magnetic properties of Nitrogen and Carbon codoped ZnO (5,0) single-walled zigzag nanotube using¯rst-principle calculations based on the density functional theory. We performed our calculations for NÀ and CÀ codoping ZnO nanotube in two di®erent con¯gurations. For the¯rst con¯guration in which the two impurity atoms (N or C) are on¯rst nearest-neighbor sites in the plane of codoping, our calculation predicts that the N-and C-codoped ZnO nanotubes are antiferromagnetic material with no net magnetization. On the other hand, it is found that for the con¯guration in which the two impurity atoms are next nearest-neighbors, a spin polarization results in a magnetic moment in the N-and C-codoped ZnO nanotubes.

In this paper, due to the importance and abundant applications of carbon nanotubes doped with boron (CNT/B 2 O 3 ) in various industries with changes in the electrical, mechanical and chemical properties, mode identification and intensity of the Raman spectra of pure and boron oxide molecule-doped spectra have been performed. The main task in this paper is to monitor the alteration of the relevant vibrational mode intensities of the pure and B-doped samples. In experimental approach, by utilizing a simple method we synthesized CNT doped with B 2 O 3 using laser ablation in liquid environment technique. The silver nanoparticles were made by the Lee-Meisel method, and then the spontaneous and surface-enhanced Raman scattering (SERS) spectra of pure and B-doped carbon nanotubes were collected. In simulation approach, using the Gauss View and Gaussian software [basis set 6-31G, computational method DFT (B3LYP)], the spontaneous and SERS spectroscopy of pure and B-doped carbon nanotubes was calculated. Due to the presence of silver nanoparticles in the vicinity of carbon nanotube and boron element, SERS intensity to spontaneous Raman (NR) intensity ratio I SERS = I NR increases in the D, G and boron oxide modes of up to 12-fold were observed. A good agreement is found between the computational and the experimental SERS results for the vibrational spectra of the synthesized composite materials.