Effect of the Dopant Configuration on the Electronic Transport Properties of Nitrogen-Doped Carbon Nanotubes

Nitrogen-doped carbon nanotubes (N-CNTs) show promise in several applications related to catalysis and electrochemistry. In particular, N-CNTs with a single nitrogen dopant in the unit cell have been extensively studied computationally, but the structure-property correlations between the relative positions of several nitrogen dopants and the electronic transport properties of N-CNTs have not been systematically investigated with accurate hybrid density functional methods. We use hybrid density functional theory and semiclassical Boltzmann transport theory to systematically investigate the effect of different substitutional nitrogen doping configurations on the electrical conductivity of N-CNTs. Our results indicate significant variation in the electrical conductivity and the relative energies of the different dopant configurations. The findings can be utilized in the optimization of electrical transport properties of N-CNTs.

Microstructure, magnetic and electronic transport properties of reactively facing-target sputtered epitaxial Mn4N films

The structure, magnetic and electronic transport properties of epitaxial Mn4N films fabricated by the facing-target reactive sputtering method have been investigated systematically. The high-quality growth of Mn4N films was confirmed by X-ray θ-2θ, pole figures and high-resolution transmission electron microscopy. The Mn4N films exhibit ferrimagnetic with strong perpendicular magnetic anisotropy. The saturation magnetization of Mn4N films decreases with increasing temperature, following the Bloch’s spin wave theory. The resistivity of Mn4N films exhibits metallic conductance mechanism. Debye temperature of Mn4N is estimated to be 85 K. The calculated residual resistivity ρxx0 of the 78.8 nm-thick Mn4N film is 30.56 μΩ cm. The magnetoresistances of Mn4N films display a negative signal and butterfly shape. The sign of anisotropic magnetoresistance (AMR) is positive, which infers that the AMR is dominated by the spin-up conduction electrons. Moreover, the transformation of fourfold to twofold symmetry for AMR and twofold to onefold symmetry for planar Hall resistivity is attributed to tetragonal crystal field effect.

Studies of Thermodynamical and Electronic Transport Properties of Na–Sn Alloy

The concept of complex formation has been incorporated in the structure of the Faber–Ziman formula for the purpose of studying the composition dependence of the electrical resistivities of Zintl alloys, which possess the anomalous nature and exhibit a large deviation from the metallic behavior around a specific composition