jz6b02437_si_001.pdf (450.6 kB)
Lower Electric Field-Driven Magnetic Phase Transition and Perfect Spin Filtering in Graphene Nanoribbons by Edge Functionalization
journal contribution
posted on 2016-11-23, 00:00 authored by M. Reza Rezapour, Jeonghun Yun, Geunsik Lee, Kwang S. KimPerfect spin filtering
is an important issue in spintronics. Although
such spin filtering showing giant magnetoresistance was suggested
using graphene nanoribbons (GNRs) on both ends of which strong magnetic
fields were applied, electric field controlled spin filtering is more
interesting due to much easier precise control with much less energy
consumption. Here we study the magnetic/nonmagnetic behaviors of zigzag
GNRs (zGNRs) under a transverse electric field and by edge functionalization.
Employing density functional theory (DFT), we show that the threshold
electric field to attain either a half-metallic or nonmagnetic feature
is drastically reduced by introducing proper functional groups to
the edges of the zGNR. From the current–voltage characteristics
of the edge-modified zGNR under an in-plane transverse electric field,
we find a remarkable perfect spin filtering feature, which can be
utilized for a molecular spintronic device. Alteration of magnetic
properties by tuning the transverse electric field would be a promising
way to construct magnetic/nonmagnetic switches.