Nanoscale edge variations observed with record-breaking resolution in magnetic nanodevices

March 28, 2013
Ferromagnetic resonance force microscopy image of the precession of an edge mode in a 500 nm diameter permalloy disk. The disk appears as a blue region, and the precession of the edge mode appears as a purple peak on the right.

( —A team of researchers from the Royal Institute of Technology, Stockholm, the University of Maryland, and the NIST Center for Nanoscale Science and Technology have measured large variations in the magnetic properties along the edge of a thin film 500 nm-diameter disk. This work represents a significant development in the measurement of magnetic thin film edge properties, which are especially important for nanodevices, such as magnetic memory cells, where the edge to area ratio is large.

The researchers' technique, called force microscopy, detects magnetic resonance in a sample through changes in the magnetic force between the sample and a magnetic cantilever tip. The technique uses an external field from a nearby microwave antenna to excite a magnetic resonance that causes the sample's magnetization to precess, wobbling like a top, billions of times per second. This precession leads to a small decrease in the time-averaged magnetization that can be detected as a change in the on the cantilever. With an external field applied in the plane of the film, modeling predicts that an "edge mode" forms in which the precession is localized to within 30 nm of the edge. The recent measurements profiled that edge mode with a record 100 nm resolution. By rotating the applied field direction, the location of the edge mode is then moved along the circumference of the disk, with changes in the mapping out variations in magnetic properties along the edge.

The researchers believe that continued development of ferromagnetic resonance force microscopy methods will enable measurements of individual magnetic nanodevices, providing important new information about the properties of these devices and their potential defects.

Explore further: New magnetic imaging technique heralds advance in spintronics

More information: Guo, F., Belova, L. and McMichael, R. Physical Review Letters 110, 017601 (2013).

Related Stories

New magnetic imaging technique heralds advance in spintronics

August 11, 2011

Impressive results from experiments at Diamond Light Source on magnetic lensless imaging by Fourier transform holography using extended references have been published today in Optics Express, the journal of the Optical Society ...

Nanoscale magnetic media diagnostics by rippling spin waves

April 3, 2012

Memory devices based on magnetism are one of the core technologies of the computing industry, and engineers are working to develop new forms of magnetic memory that are faster, smaller, and more energy efficient than today's ...

New method for imaging defects in magnetic nanodevices

September 13, 2012

(—A team of researchers from the NIST Center for Nanoscale Science and Technology, the Royal Institute of Technology, Stockholm, and the University of Maryland have demonstrated a microscopy method to identify ...

Recommended for you

Physicists develop new technique to fathom 'smart' materials

November 26, 2015

Physicists from the FOM Foundation and Leiden University have found a way to better understand the properties of manmade 'smart' materials. Their method reveals how stacked layers in such a material work together to bring ...

Mathematicians identify limits to heat flow at the nanoscale

November 24, 2015

How much heat can two bodies exchange without touching? For over a century, scientists have been able to answer this question for virtually any pair of objects in the macroscopic world, from the rate at which a campfire can ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.