Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



Home > Press > New kind of MRI enables study of magnets for computer memory

Chris Hammel
Chris Hammel

Abstract:
What is there to see inside a magnet that's smaller than the head of a pin?

Quite a lot, say physicists who've invented a new kind of MRI technique to do just that.

The technique may eventually enable the development of extremely small computers, and even give doctors a new tool for studying the plaques in blood vessels that play a role in diseases such as heart disease.

New kind of MRI enables study of magnets for computer memory

Columbus, OH | Posted on July 17th, 2008

In a recent issue of Physical Review Letters, the scientists report the first-ever magnetic resonance image of the inside of an extremely tiny magnet.

Specifically, the magnet is a "ferromagnet" -- a magnet made of ferrous metal such as iron. It's what most people think of when they hear the word "magnet."

"The magnets we study are basically the same as a refrigerator magnet, only much smaller," said project leader Chris Hammel, Ohio Eminent Scholar in Experimental Physics at Ohio State University. The disk-shaped magnets in this study measured only two micrometers (millionths of a meter) across.

"Because ferromagnets generate such strong magnetic fields, we can't study them with typical MRI. A related technique, ferromagnetic resonance, or FMR, would work, but it's not sensitive enough to study individual magnets that are this small."

Likewise, medical researchers can't use MRI to image plaques formed in the body, because plaques are too small. That's why this new kind of magnetic resonance could eventually become a tool for biomedical research.

The technique combines three different kinds of technology: MRI, FMR, and atomic force microscopy.

They dubbed the technique "scanned probe ferromagnetic resonance force microscopy," or scanned probe FMRFM, and it involves detecting a magnetic signal using a tiny silicon bar with an even tinier magnetic probe on its tip.

As the probe passes over a material, it captures a bowl-shaped image: a curved cross-section of an object. The magnetic signal is more intense in the middle (the "bottom" of the bowl), and fades away toward the edges.

It may sound like an odd configuration, but that's why the new technique works.

Every atom emits radio waves at a particular frequency. But to know where those atoms are, scientists need to be able to localize where the radio waves are coming from.

Large-scale MRI machines, such as those in hospitals, get around this problem by varying the magnetic field by precise amounts as it sweeps over an object. The computer controlling the MRI knows that where the magnetic field equals X, the location equals Y. Sophisticated software combines the data, and doctors get a 3D view inside a patient's body.

For Hammel's tiny magnets, no methods were previously known that would image the inside of them, much less allow for precise localization. But since the new probe system generates a magnetic field that varies naturally, the physicists discovered that they could sweep the probe over an array of magnets and get a 2D view that's similar to a medical MRI. In Physical Review Letters, they reported an image resolution of 250 nanometers (billionths of a meter).

Now that they have their imaging technique, Hammel and his team are beginning to record the properties of many different kinds of tiny magnets -- a critical first step toward developing them for computer memory.

Experts believe that one day, tiny magnets could be implanted on a computer's central processing unit (CPU) chip. Because system data could be recorded on the magnets, such a computer would never need to boot up. It would also be very small; essentially, the entire computer would be contained in the CPU.

For biomedical research, the technique could be used to study tissue samples taken from plaques that form in brain tissues and arteries in the body. Many diseases are associated with plaques, including Alzheimer's and atherosclerosis. Currently, researchers are trying to study the structure of plaques in detail to understand how they form and how they affect conventional MRI images.

Hammel and his team hope to contribute to the development of an instrument that could be sold and used routinely in laboratories. But the technique needs some further development before it could become an everyday tool for the computer industry or for biomedicine.

Hammel's Ohio State coauthors on the paper include Yuri Obukhov, a research associate; Thomas Gramila, associate professor of physics; Denis Pelekhov, a research scientist in the university's Institute for Materials Research; Palash Banerjee, a postdoctoral researcher; and Jongjoo Kim and Sanghun An, both doctoral students. They collaborated with Ivar Martin, Evgueni Nazaretski and Roman Movshovich of Los Alamos National Laboratory; and Sharat Batra of Seagate Research, the research and development center of hard drive manufacturer Seagate Technologies.

This work was funded by the Department of Energy.

####

For more information, please click here

Contacts:
P. Chris Hammel
(614) 247-6928


Written by
Pam Frost Gorder
(614) 292-9475

Copyright © Ohio State University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Researchers develop artificial building blocks of life March 8th, 2024

How surface roughness influences the adhesion of soft materials: Research team discovers universal mechanism that leads to adhesion hysteresis in soft materials March 8th, 2024

Two-dimensional bimetallic selenium-containing metal-organic frameworks and their calcinated derivatives as electrocatalysts for overall water splitting March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

Imaging

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

First direct imaging of small noble gas clusters at room temperature: Novel opportunities in quantum technology and condensed matter physics opened by noble gas atoms confined between graphene layers January 12th, 2024

The USTC realizes In situ electron paramagnetic resonance spectroscopy using single nanodiamond sensors November 3rd, 2023

Observation of left and right at nanoscale with optical force October 6th, 2023

Memory Technology

Interdisciplinary: Rice team tackles the future of semiconductors Multiferroics could be the key to ultralow-energy computing October 6th, 2023

Researchers discover materials exhibiting huge magnetoresistance June 9th, 2023

Rensselaer researcher uses artificial intelligence to discover new materials for advanced computing Trevor Rhone uses AI to identify two-dimensional van der Waals magnets May 12th, 2023

TUS researchers propose a simple, inexpensive approach to fabricating carbon nanotube wiring on plastic films: The proposed method produces wiring suitable for developing all-carbon devices, including flexible sensors and energy conversion and storage devices March 3rd, 2023

Discoveries

What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024

Researchers’ approach may protect quantum computers from attacks March 8th, 2024

High-tech 'paint' could spare patients repeated surgeries March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

Announcements

What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

The Access to Advanced Health Institute receives up to $12.7 million to develop novel nanoalum adjuvant formulation for better protection against tuberculosis and pandemic influenza March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project