Electron-Conduction Properties of Fe−Al Alloy Nanowires

Electronic transport properties of PbSi Schottky-clamped transistors with a surrounding metal–insulator gate

Sustaining Moore's law requires the design of new materials and the construction of FET.

Fe/Ni core/shell nanowires and nanorods: a combined first-principles and atomistic simulation study

In recent years, construction and characterization of core-shell structures have attracted great attention because of their unique functional properties and their integration into technological devices. However, some aspects of their basic physics still remain to be explored. In this study, we report on an extensive hierarchical multiscale modeling methodology applied to Fe-Ni core/shell nanostructures of technological interest. As a first step, supported on a first-principles study, we develop a methodology to compute primordial but unprecedented parameters such as the exchange coupling and the equilibrium bond distances at the interface, namely J_Fe-Ni = 35.48 meV and d = 2.5 Å. This methodology can be used for computing fundamental parameters in mixed systems by knowing the parameters in the bulk samples, and the so-obtained results can be used in higher size scale simulations. As a proof, the results obtained are used as input parameters for atomistic simulations on Fe-Ni samples made out of a Fe core surrounded by a Ni shell whose external diameter varies finely in the range 60-110 nm. The inner diameter and height are fixed to be 40 and 50 nm, respectively. We address the structural, electronic, static magnetic and hysteresis properties of the Fe-Ni core/shell cylindrical nanostructures in different size ranges. These nanostructures reveal different magnetic properties with novel complex states, which are studied in detail.

Stability and clusterization of hydrogen-vacancy complexes in B2-FeAl: insight from hydrogen embrittlement

Isotropic hydrogenated vacancy-clusters induced hydrogen embrittlement in FeAl.

Electronic transport properties of ultra-thin Ni and Ni-C nanowires

The structures and electronic transport properties of ultra-thin Ni and Ni-C nanowires obtained from carbon nanotube (CNT) templates are theoretically investigated. C atoms tend to locate at the central positions of nanowires and are surrounded by Ni atoms. Spin polarization at the Fermi level is not responsible for the spin filtration of these nanowires. Increasing C concentration can improve the resistance of nanowires by abating the number of electronic transmission channels and the coupling of electron orbitals between Ni atoms. Moreover, with the increase of diameter, the conductance of these nanowires increases as well. This study is helpful for guiding the synthesis of nanowires with desired applications.

Position effects of single vacancy on transport properties of single layer armchair h-BNC heterostructure

Based on certain single layer armchair h-BNC heterostructures, six molecular devices with different positions of single vacancy atoms are investigated to explain the modulating process of negative differential resistance (NDR) behaviors and rectifying performance. The results show that NDR behaviors can be observed clearly with vacancy atoms near the interface of graphene nano-ribbon and BN nano-ribbon, and rectifying performance can be enhanced obviously when there are vacancy atoms in the moiety of the BN nano-ribbon. The first-principles analysis of the microscopic nature reveals that strength of electronic transmission, evolutions of molecular orbitals and distributions of molecular states are the intrinsic responses to these transport properties.

Theoretical study of hierarchical structures and heredity effect of silicon solidifying on carbon nanotube

The growth of silicon atoms at the heterogeneous surface of carbon nanotubes (CNTs) is studied by means of molecular dynamics simulations. The results indicate that silicon atoms are concentrated to form an “annual ring” structure around CNTs. The structures of CNTs have strong correlation with the stacking sequence of silicon atoms. Heredity effect can be clearly observed during the heterogeneous nucleation. The uniform internal potential field around CNTs results in the formation of annual ring structures.