Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nanoscale magnetic media diagnostics by rippling spin waves

04.04.2012
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 flash and SDRAM memory.

They now have a new tool developed by a team from the National Institute of Standards and Technology (NIST), the University of Maryland Nanocenter and the Royal Institute of Technology in Sweden — a method to detect defects in magnetic structures as small as a tenth of a micrometer even if the region in question is buried inside a multilayer electronic device.*


Trapped beneath the magnetic tip of a microscale cantilever, spin waves can be used to non-destructively measure the properties of magnetic materials and search for nanoscale defects, especially in multilayer magnetic systems like a typical hard drive, where defects could be buried beneath the surface. Credit: McMichael/NIST

The technique demonstrated at the NIST Center for Nanoscale Technology (CNST) builds on work by researchers at the Ohio State University.** The idea is to trap and image oscillating perturbations of a magnetic field—"spin waves"—in a thin film. Trapped spin waves provide scientists with a powerful new tool to nondestructively measure the properties of magnetic materials and search for nanoscale defects that could or have caused memory failures, especially in multilayer magnetic systems like a typical hard drive, where defects could be buried beneath the surface.

According to NIST researcher Robert McMichael, when left alone, the material's magnetization is like the surface of a pond on a windless day. The pond is comprised of smaller magnetic moments that come with the quantum mechanical "spin" of electrons. Tap the surface of the pond with a piece of driftwood, or microwaves in this case, and the surface will begin to ripple with spin waves as the microwave energy jostles the spins, which, in turn, jostle their neighbors.

"The trick we play is to tune the microwaves to a frequency just outside the band where the spin waves can propagate—except right under our magnetic probe tip," says McMichael. "It's like the pond is frozen except for a little melted spot that we can move around to check magnetic properties at different spots in the sample."

The trapped spin waves are disturbed by defects in the material, and this effect allows the defects to be characterized on 100 nm length scales.

Previous work had shown this same effect in magnetic spins that were oriented perpendicular to the magnetic film surface, meaning that the individual spins coupled strongly with their neighbors, which limited the resolution. This new work adds the extra feature that the magnetic spins are aligned in plane with one another and are not as tightly coupled. This setup is not only more representative of how many magnetic devices would be structured, but also allows for tighter focusing and better resolution.

* H-J. Chia, F. Guo, L.M. Belova and R. D. McMichael. Nanoscale spin wave localization using ferromagnetic resonance force microscopy. Physical Review Letters. 108, 087206 (2012). http://prl.aps.org/pdf/PRL/v108/i8/e087206.

** See Lee et al. Nanoscale scanning probe ferromagnetic resonance imaging using localized modes. Nature. 466, 12. Aug. 12, 2010. doi:10.1038/nature09279.

Mark Esser | EurekAlert!
Further information:
http://www.nist.gov

More articles from Physics and Astronomy:

nachricht New quantum liquid crystals may play role in future of computers
21.04.2017 | California Institute of Technology

nachricht Light rays from a supernova bent by the curvature of space-time around a galaxy
21.04.2017 | Stockholm University

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

Im Focus: Quantum-physical Model System

Computer-assisted methods aid Heidelberg physicists in reproducing experiment with ultracold atoms

Two researchers at Heidelberg University have developed a model system that enables a better understanding of the processes in a quantum-physical experiment...

Im Focus: Glacier bacteria’s contribution to carbon cycling

Glaciers might seem rather inhospitable environments. However, they are home to a diverse and vibrant microbial community. It’s becoming increasingly clear that they play a bigger role in the carbon cycle than previously thought.

A new study, now published in the journal Nature Geoscience, shows how microbial communities in melting glaciers contribute to the Earth’s carbon cycle, a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

New quantum liquid crystals may play role in future of computers

21.04.2017 | Physics and Astronomy

A promising target for kidney fibrosis

21.04.2017 | Health and Medicine

Light rays from a supernova bent by the curvature of space-time around a galaxy

21.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>