Depinning of domain walls in permalloy nanowires with asymmetric notches.
Effective control of the domain wall (DW) motion along the magnetic nanowires is of great importance for fundamental research and potential application in spintronic devices. In this work, a series of permalloy nanowires with an asymmetric notch in the middle were fabricated with only varying the width (d) of the right arm from 200 nm to 1000 nm. The detailed pinning and depinning processes of DWs in these nanowires have been studied by using focused magneto-optic Kerr effect (FMOKE) magnetometer, magnetic force microscopy (MFM) and micromagnetic simulation. The experimental results unambiguously exhibit the presence of a DW pinned at the notch in a typical sample with d equal to 500 nm. At a certain range of 200 nm < d < 500 nm, both the experimental and simulated results show that the DW can maintain or change its chirality randomly during passing through the notch, resulting in two DW depinning fields. Those two depinning fields have opposite d dependences, which may be originated from different potential well/barrier generated by the asymmetric notch with varying d.
National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, P. R. China.
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Y
Gao
National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, P. R. China.|Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, P. R. China.
B
B
You
School of Electronic Science and Engineering, Nanjing University, Nanjing 210046, P. R. China.
X Z
XZ
Ruan
School of Electronic Science and Engineering, Nanjing University, Nanjing 210046, P. R. China.
M Y
MY
Liu
Key Laboratory of Magnetic Materials and Devices &Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, P. R. China.
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HL
Yang
Key Laboratory of Magnetic Materials and Devices &Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, P. R. China.
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QF
Zhan
Fert Beijing Institute, Beihang University, Beijing, P. R. China.|School of Electronic and Information Engineering, Beihang University, Beijing, China.
Z
Z
Li
Fert Beijing Institute, Beihang University, Beijing, P. R. China.|School of Electronic and Information Engineering, Beihang University, Beijing, China.
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N
Lei
Fert Beijing Institute, Beihang University, Beijing, P. R. China.|School of Electronic and Information Engineering, Beihang University, Beijing, China.
W S
WS
Zhao
National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, P. R. China.
D F
DF
Pan
National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, P. R. China.
J G
JG
Wan
Department of Physics, University of York, York YO10 5DD, United Kingdom.
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J
Wu
National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, P. R. China.
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HQ
Tu
National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, P. R. China.
J
J
Wang
National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, P. R. China.
W
W
Zhang
School of Electronic Science and Engineering, Nanjing University, Nanjing 210046, P. R. China.
Y B
YB
Xu
National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, P. R. China.|Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, P. R. China.
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Du