A Computational Investigation on the Structural, Thermodynamic, Electrical, Magnetic, and Optical Properties of Transition Metal (Cr & Mo)-Doped Aluminum Nitride Nanotubes Using Density Functional Theory

In the era of nanotechnology, a wide range of theoretical and experimental research has been performed on different aluminum nitride nanotubes for their great acceptance in advanced technology and biomedical applications. In this work, the structural, thermodynamic, electrical, magnetic and optical properties of aluminum nitride nanotubes (AlNNT) have been investigated before and after doping them individually with transition metals (TM), Cr and Mo. From the analysis of electronic properties, it has been observed that the doping transition metal with pristine Al[Formula: see text]N[Formula: see text] nanotube causes a significant increase in the electrical conductivity of the nanotubes, which signifies their potential to be used in optoelectronic devices and solar cells. According to the study of thermodynamic properties, doping of TMs causes more stability in a pristine structure. Moreover, from the study of IR spectroscopy, no imaginary frequency has been observed for any of the pristine and TM-doped aluminum nitride nanotubes, which signifies that all nanotubes will form true energy minima and the most stable state. According to the DOS analysis, the TM-doped nanotubes show splitting of their molecular orbitals, indicating their potential for use in spintronic devices. All calculations in this study were obtained by employing the density functional theory (DFT) with B3LYP hybrid exchange correlational functional using the LanL2DZ basis set. The doping was done by replacing an Al or [Formula: see text] atom from the nanotube with Cr or Mo, thus forming four nanotubes. The pristine and the doped nanotubes were optimized to the minimum ground state energy of their corresponding structure to obtain maximum structural stability.