Skip to main content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.


The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Dynamic Lorentz Microscopy of Micromagnetic Structure in Magnetic Tunnel Junctions



Justin M. Shaw, R.H. Geiss, Stephen E. Russek


Lorentz microscopy was used to study the micromagnetic structure and magnetization reversal in magnetic tunnel junctions (MTJs) fabricated with different processing conditions including a preoxidation process. The authors find that the free layer in a MTJ has considerably more disorder than that seen in an isolated magnetic layer. The disorder changes with anneals that set the exchange bias, suggesting that the disorder arises from the antiferromagnetic layer and is transferred to the free layer by magnetostatic Neel coupling. The disorder and time-dependent fluctuations in the magnetic structure provide a foundation for understanding several sources of 1/f{I/} noise in MTJs.
Applied Physics Letters


Lorentz microscopy, magnetic tunnel junction, magnetization reversal, micromagnetic, mtj, Neel, ripple
Created November 20, 2006, Updated February 19, 2017