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

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.

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  1. Re:I'm strangly attracted to this concept. by Gizan · · Score: 3, Informative

    You win the internet so far this morning.