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New Class of "Non-Joulian" Magnets Change Volume In Magnetic Field

Posted by Soulskill on from the polarizing-research dept.

Zothecula notes an announcement from the University of Maryland saying they have developed a new class of magnets, called "Non-Joulian" magnets, which physically expand in the presence of a magnetic field. "In the 1840s, physicist James Prescott Joule discovered that iron-based magnetic materials changed their shape but not their volume when placed in a magnetic field. This phenomenon is referred to as "Joule Magnetostriction," and since its discovery 175 years ago, all magnets have been characterized on this basis." Another significant property of these new magnets is that they can harvest or convert energy with very little waste heat (abstract). The magnets are created when thermally-treated, iron-based alloys are heated in a furnace, then rapidly cooled. When they reach room temperature, they have an odd, almost cellular shape on the microscopic level. The researchers say the magnets have numerous applications for energy-efficient sensors and actuators.

3 of 39 comments (clear)

  1. Publicly Funded Research by konohitowa · · Score: 5, Insightful

    According to the articles, the alloy isn't particularly exotic and the processing isn't difficult. I'd love to know what they specifically used. Sadly, they published in Nature. So I can view the paper for $5 or download as PDF for $32. Or, you know, subscribe for $200. What I don't get is why I, as one of the millions of taxpayers that funded this research, don't have free access to the paper.

    Yes. I know. Preaching to the choir, OA journals, etc. That still doesn't change the fact that I find this both irritating and wrong.

    1. Re:Publicly Funded Research by konohitowa · · Score: 3, Insightful

      When you say "go to a library" you are implying that everyone has access to a University library or similarly large, well-funded location. Not all libraries have access to journals. Although I don't have a reference for this, I suspect that the vast majority of libraries don't. I'm fortunate in the fact that I can spend an hour of total travel time (granted, 20 minutes of this will be spent waiting for the train) to get to a major University. I envision that one day there will be a series of tubes that give us access to this type of information from nearly anywhere and not a severely limited number of physical locations.

    2. Re:Publicly Funded Research by konohitowa · · Score: 3, Insightful

      He did more than just think it.