Related Experiment Video
Updated: Apr 21, 2026
10:39
Reconfigurable Microfluidic Channel with Pin-discretized Sidewalls
Published on: April 12, 2018
9.9K
Domain wall pinning in ultra-narrow electromigrated break junctions
Robert M Reeve1, André Loescher, Mohamad-Assaad Mawass
1Institut für Physik, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany.
Summary
Domain wall pinning strength increases as constriction width decreases in nanoscale ferromagnetic junctions. This study clarifies intrinsic magnetic behavior by minimizing measurement artifacts in electromigrated Permalloy structures.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Nanotechnology
Background:
- Studying magnetic domain walls in confined geometries is crucial.
- Artifacts in nanoscale magnetic systems can obscure intrinsic magnetic effects.
Purpose of the Study:
- Investigate domain wall depinning in electromigrated ferromagnetic junctions.
- Analyze the effect of constriction width on domain wall pinning.
Main Methods:
- Fabricated and tailored Ni(80)Fe(20) (Permalloy) notched half-ring structures in ultra-high vacuum.
- Controlled in-situ electromigration to adjust constriction width.
- Measured domain wall depinning field and its angular dependency.
Main Results:
- Domain wall pinning strength increases with reduced contact size.
- Domain wall energy decreases in narrower constrictions.
- Determined the full pinning potential by measuring depinning field symmetry.
Conclusions:
- Electromigration is an effective in-situ technique for tailoring nanoscale magnetic devices.
- Constriction width significantly influences domain wall pinning behavior.
- Understanding pinning potential is key for controlling magnetic domain walls in nanostructures.
Related Concept Videos
01:24Metal-Semiconductor Junctions
1.4K
The contact of metal and semiconductor can lead to the formation of a junction with either Schottky or Ohmic behavior.
Schottky Barriers
Schottky barriers arise when a metal with a work function (Φm) contacts a semiconductor with a different work function (Φs). Initially, electrons transfer until the Fermi levels of the metal and semiconductor align at equilibrium. For instance, if Φm > Φs, the semiconductor Fermi level is higher than the metal's before contact. The...
Schottky Barriers
Schottky barriers arise when a metal with a work function (Φm) contacts a semiconductor with a different work function (Φs). Initially, electrons transfer until the Fermi levels of the metal and semiconductor align at equilibrium. For instance, if Φm > Φs, the semiconductor Fermi level is higher than the metal's before contact. The...
1.4K
01:11P-N junction
1.6K
A p-n junction is formed when p-type and n-type semiconductor materials are joined together. At the interface of the p-n junction, holes from the p-side and electrons from the n-side begin to diffuse into the opposite sides due to the concentration gradient. This diffusion of carriers leads to a region around the junction where there are no free charge carriers, known as the depletion region. The charge density within the depletion region for the n-side and p-side can be described by the...
1.6K
01:27Biasing of Metal-Semiconductor Junctions
896
Biasing metal-semiconductor junctions involves applying a voltage across the junction. Specifically, the metal is connected to a voltage source, while the semiconductor is grounded. This technique is essential for controlling the direction and magnitude of current flow in electronic devices, including diodes, transistors, and photovoltaic cells.
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...
896
01:16Biasing of P-N Junction
2.7K
The operation of a p-n junction diode involves various biasing conditions, including forward bias, reverse bias, and equilibrium.
In equilibrium, no external voltage is applied across the p-n junction. The depletion region is formed at the junction interface due to the diffusion of carriers, which leaves behind charged dopants, acceptors on the p-side, and donors on the n-side. These immobile charges create an electric field that prevents further diffusion of carriers. The related energy band...
In equilibrium, no external voltage is applied across the p-n junction. The depletion region is formed at the junction interface due to the diffusion of carriers, which leaves behind charged dopants, acceptors on the p-side, and donors on the n-side. These immobile charges create an electric field that prevents further diffusion of carriers. The related energy band...
2.7K
01:22MOSFET: Enhancement Mode
1.1K
Enhancement-mode MOSFETs are pivotal components in electronics, distinguished by their capacity to act as highly efficient switches. They are part of the larger family of metal-oxide Semiconductor Field-Effect Transistors (MOSFETs). They are available in two types: p-channel and n-channel, each tailored to specific polarity operations.
In their basic form, enhancement-mode MOSFETs are typically non-conductive when the gate-source voltage (Vgs) is zero. This default 'off' state means no...
In their basic form, enhancement-mode MOSFETs are typically non-conductive when the gate-source voltage (Vgs) is zero. This default 'off' state means no...
1.1K
01:32Pinching-off of Coated Vesicles
3.1K
Vesicle budding is orchestrated by distinct cytosolic proteins such as adaptor proteins, coat proteins, and GTPases. To initiate vesicle budding, membrane-bending proteins containing crescent-shaped BAR domains bind to the lipid heads in the bilayer and distort the membrane to form a protein-coated vesicle bud. Adaptors proteins such as AP2 for clathrin-coated vesicles can nucleate on the deformed membrane. Finally, coat proteins such as clathrin or COPI and COPII assemble into a coat forming...
3.1K