Spin-dependent transport through a magnetic carbon nanotube-molecule junction

Abstract

The electronic structure and spin-dependent conductance of a magnetic junction consisting of two Fe-doped carbon nanotubes and a C60 molecule are investigated using a first-principles approach that combines the density functional theory with the nonequilibrium Greens function technique. The tunneling magnetoresistance ratio is found to be 11%. The density of states and transmission coefficient through the molecular junction are analyzed and compared to layered magnetic tunneling junctions. Our findings suggest new possibilities for experiments and for future technology.

Strain effects on work functions of pristine and potassium-decorated carbon nanotubes

“…Work functions of CNT (5,5) and CNT(9,0) without strain are estimated by our calculations to be 4.38 eV and 4.40 eV respectively, which are consistent with previous studies. 9,12 We found that strain has great effects on work functions of both CNTs, and when strained, the work function of CNT (5,5) behaves very differently from that of CNT (9,0) as shown in Fig. 2.…”

“…They have been regarded as great candidates for building blocks of future nanoscale electronic and photonic devices due to their remarkable electronic properties. In last two decades, large amounts of CNT-based devices such as field effect transistors, 2,3 diodes, 4 tunneling magnetoresistance junctions, 5,6 and field emitters 7,8 have been proposed experimentally or theoretically. A complete understanding of electronic properties of CNTs and their dependence on various kinds of physical or chemical conditions holds the key for the future design and applications of these devices.…”

“…In this paper, we present our theoretical investigations under the framework of density functional theory (DFT) on correlations between uniaxial strain and work functions of pristine and potassium-decorated CNT (5,5) and CNT (9,0). For pristine cases, we found that the strain has strong effects on work function for both CNTs, and CNT (5,5) responds to the strain distinctly different from CNT (9,0) does. When coated with potassium, our calculations showed that the strain dependence of work function for both CNTs changes drastically.…”

Ab initiostudy of spin-dependent transport in carbon nanotubes with iron and vanadium adatoms

“…A few studies have been published on electron transport in this context. Iron-SWNT junctions with C 60 molecules 23 and pristine SWNTs 24 have been proposed as magnetic tunnel junctions. First-principles transport calculations yield tunnel magnetoresistances of 11% and 40%, respectively, for these systems.…”

C-doped ZnO nanowires: Electronic structures, magnetic properties, and a possible spintronic device

“…As a result, reasonably high magnetic moments of two leads are normally necessary for high TMR ratio. 22 The origin of the high TMR ratio in the proposed TMJ is its unique magnetic interfaces between the center and two leads. Therefore, the strength of magnetic moments of two leads is not essential for high TMR ratio.…”