Neeraj K. Jaiswal

Fe-Doped Armchair Graphene Nanoribbons for Spintronic/Interconnect Applications

In this study, we investigate structural stability, and electronic and transport properties of Fe terminated/doped armchair graphene nanoribbons (AGNR) through first-principles calculations based on density functional theory. Results show that substitutional Fe impurities have a stable bonding with AGNR and center of the ribbon is regarded as the most preferred doping site. The observed magnetic moment of an Fe atom varies from 1.95 μB to 2.93 μB depending upon the doping site. The electronic structure calculations reveal breaking of degeneracy for the opposite spin states which is further supported by the density of states and the projected density of state analysis. Spin polarization of 60% was obtained which can be tuned by varying the position of Fe atoms. Moreover, there exist a number of conduction channels crossing the Fermi level and thereby causing high metallicity for all the ribbons irrespective of ribbon widths or the position of Fe impurity. The observed high metallic behavior is further confirmed by the transmission spectrum and current versus voltage ( I-V) calculations. The present results show the potential of considered nanoribbons for the spintronic/interconnect applications.

Possibility of spin-polarized transport in edge fluorinated armchair boron nitride nanoribbons

We predict the possibility of spin based electronic transport in edge fluorinated armchair boron nitride nanoribbons (ABNNRs). The structural stability, electronic and magnetic properties of these edge fluorinated ABNNRs have been systematically analyzed by means of first-principles calculations within the local spin-density approximation (LSDA). Regardless of their width, ABNNRs with F-passivation at only the edge-B atoms are found to be thermodynamically stable and half-metallic in nature. The spin polarized states are found to be ∼0.4 eV more stable than that of spin compensated states. Further, upto 100% spin polarization is expected in ABNNRs with F-passivation at only the edge-B atoms as indicated by the giant splitting of spin states which is observed in the corresponding band structures, DOS and transmission spectrum. The existence of half-metallicity is attributed to the localization of electronic charge at unpassivated edge-N atoms as revealed from the analysis of Bloch states and projected density of states (PDOS). Importantly, present stability analysis suggests that the possibility of experimental realization of spin polarized transport in ABNNRs is more promising via F-passivation of ribbon edges than that of H-passivation. The observed half-metallic nature and large difference in the energies (∼0.4 eV) of spin polarized and spin compensated states projects these half-metallic ABNNRs as potential candidates for inorganic spintronic applications.

Structural, magnetic and electronic properties of armchair graphene nanoribbons interacting with Co: DFT investigations

ABSTRACT Theoretical investigations based on density functional theory (DFT) have been performed to reveal the effect of Co impurities on structural stability, magnetic and electronic properties of armchair graphene nanoribbons (AGNR). It is revealed that Co forms stable chemical bonding with host (C) atoms and settled in magnetic ground state. Calculated magnetic moment per Co atom was found to be 1.02–1.67 µB. Moreover, up to ∼70% spin polarization is also predicted which is a function of doping site. Present findings are useful to induce width independent metallicity in AGNR making them a potential candidate for contact/interconnect applications in upcoming nano-devices.

Spintronic and transport properties of linear atomic strings of transition metals (Fe, Co, Ni)

In the present work, first-principles investigations have been performed to study the spintronic and transport properties of linear atomic strings of Fe, Co and Ni. The structural stabilities of the considered strings were compared on the basis of binding energies which revealed that all the strings are energetically feasible to be achieved. Further, all the considered strings are found to be ferromagnetic and the observed magnetic moment ranges from 1.38 to 1.71 μB. The observed transport properties and high spin polarization points towards their potential for nano interconnects and spintronic applications.

Intrinsic Half-metallicity in Edge Fluorinated Armchair Boron Nitride Nanoribbons

We predict intrinsic half-metallicity in armchair boron nitride nanoribbons (ABNNRs) via edge fluorination. The stability, electronic and magnetic properties of bare and edge fluorinated ABNNRs have been systematically analyzed by means of first-principles calculations within the local spin-density approximation (LSDA). The ribbons whose only edge-B atoms passivated with F atoms (i.e., edge-N atoms are un-passivated), regardless of width, are found half-metallic with a half-metal gap of 0.3 eV. A 100 \% spin polarized charge transport across the Fermi level is expected for such ribbons as the spin polarized states are

Transport properties of cu-doped armchair graphene nanoribbons in two probe geometry

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First principles study of adsorbed and substitutionally doped Fe atoms in zigzag graphene nanoribbons

0.4 eV more stable than the spin un-polarized states and only single-spin conducting channels are present across the Fermi level owing to the gigantic spin splitting. The existence of half-metallicity is attributed to the localization of electronic charge at bare edge-N atoms as revealed from the analysis of Bloch states and projected density of states (PDOS).The sufficiently large half-metal gap (0.3 eV) with huge difference in the energies (

First Principle Calculations of Absorption of Cu‐Doped Boron Nanotube

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First principles calculations of cobalt doped zigzag graphene nanoribbons

0.4 eV) of spin polarized and spin compensated states projects these half-metallic ABNNRs as potential candidate for spintronics applications.

First principles calculations of armchair graphene nanoribbons interacting with Cu atoms

Copper doped armchair graphene nanoribbons are investigated using density functional theory. Coinage metal, Cu is doped at one edge as a substitutional dopant and transport properties are investigated and compared with pristine ones. The current-voltage characteristics are enhanced due to the Cu-doping with negative resistance being observed at higher biases. In the transmission spectrum, a typical step like behavior has been observed in pristine AGNR whereas the T.S is greatly enhanced at the Fermi level in Cu-doped AGNR.