Spin Valve Effect of 2D‐Materials Based Magnetic Junctions

Abstract

The magnetotransport properties of spin valve structure are highly influenced by the type of intervening layer inserted between the ferromagnetic electrodes. In this scenario, spin filtering effect at the interfaces plays a crucial role in determining the magnetoresistance (MR) of such magnetic structures, which can be enhanced by using a suitable intervening layer. Here, the authors investigate the spin filtering effect of the two-dimensional layers such as hexagonal boron nitride (hBN), graphene (Gr), and Gr-hBN hybrid system for modifying the magnetotransport characteristics of the vertical spin valve architectures (Ni/hBN/Ni, Ni/Gr/Ni, and Ni/Gr-hBN/Ni). Compared to graphene, hBN incorporated magnetic junction reveals higher MR and spin polarizations (P) suggesting better spin filtering at the interfaces. The MR for hBN incorporated junction is calculated to be %0.83%, while that of graphene junction it is estimated to be %0.16%. Similar contrast is observed in the 'P' of ferromagnets (FMs) for the two junctions, that is, %6.4% for hBN based magnetic junction and %2.8% for graphene device. However, for Gr-hBN device, the signal not only get inverts, but it also suggests efficient spin filtering mechanism at the FM interfaces. Their results can be useful to comprehend the origin of spin filtering and the choice of non-magnetic spacer for magnetotransport characteristics.

High magnetoresistance of a hexagonal boron nitride–graphene heterostructure-based MTJ through excited-electron transmission

“…A fabrication of graphene-hBN van der Waals heterostructure has been further developing, and the creation of the graphene-hBN heterostructure has been possible 32 . Previous experimental study shows the use of graphene-hBN heterostructure as a tunnel barrier of 2D materials based MTJ and found an increasing performance compared with that of graphene or hBN based MTJs, as well as a unique inverted signal of the spin valve, have been found 33 . The unique chemical and physical properties are expected between the interface and insulator barrier.…”

Negative Magnetoresistance Behavior in Polymer Spin Valves Based on Donor−Acceptor Conjugated Molecules

“…[ 69–71 ] Concept of spin filtering was also used for explanation toward reversed MR signals as recently discovered in molecular spin valves exploiting organic radical self‐assembled monolayer and 2D materials. [ 72–76 ] Since our negative MR response is contributed by bulk spin transport rather than spinterface engineering, we prefer to use “filtering‐like” term to define such spin reversal activity of bulk spin transport. This is the first report on such fascinating spin phenomenon in solution‐processed conjugated D–A polymers.…”

Building Functional Memories and Logic Circuits with 2D Boron Nitride

“…investigated the spin filtering effect of vertical magnetic tunneling junctions, i.e., Ni/h‐BN/Ni, Ni/graphene/Ni, and Ni/graphene–BN/Ni, respectively. [ 289 ] The magnetoresistance and spin polarization for h‐BN incorporated junction were 0.83% and 6.4%, while that of graphene junction were 0.16% and 2.8%. The results revealed that Ni/h‐BN junctions had higher spin filtering efficiency, compared with Ni/graphene junctions, as depicted in Figure 15h.…”