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Supercomputers Help Researchers Find Two New Kinds Of Magnets (phys.org)
"Predicting magnets is a heck of a job, and their discovery is very rare," said a mechanical engineering professor at Duke University. But after years of work synthesizing various predictions, material scientists "predicted and built two new magnetic materials, atom-by-atom, using high-throughput computational models." An anonymous reader quotes Phys.org:
The success marks a new era for the large-scale design of new magnetic materials at unprecedented speed. Although magnets abound in everyday life, they are actually rarities -- only about 5% of known inorganic compounds show even a hint of magnetism. And of those, just a few dozen are useful in real-world applications because of variability in properties such as effective temperature range and magnetic permanence...
In a new study, materials scientists from Duke University provide a shortcut in this process. They show the capability to predict magnetism in new materials through computer models that can screen hundreds of thousands of candidates in short order. And, to prove it works, they've created two magnetic materials that have never been seen before.
"The first alloy is particularly interesting," reports the International Business Times, "because it contains no rare-earth materials, which are both expensive and difficult to acquire." But a Duke mechanical engineering professor points out that "It doesn't really matter if either of these new magnets proves useful in the future. The ability to rapidly predict their existence is a major coup and will be invaluable to materials scientists moving forward."
In a new study, materials scientists from Duke University provide a shortcut in this process. They show the capability to predict magnetism in new materials through computer models that can screen hundreds of thousands of candidates in short order. And, to prove it works, they've created two magnetic materials that have never been seen before.
"The first alloy is particularly interesting," reports the International Business Times, "because it contains no rare-earth materials, which are both expensive and difficult to acquire." But a Duke mechanical engineering professor points out that "It doesn't really matter if either of these new magnets proves useful in the future. The ability to rapidly predict their existence is a major coup and will be invaluable to materials scientists moving forward."
Not rare but they produce a ton of toxic waste being processed. It all went to China because they could do it cheaper and eat the toxic waste, too.
When China were embargoing exports (or talking about it) there was talk of granting exceptions to a closed mine in California to re-open as a strategic hedge.
Exerting force requires energy, no?
No. A force does not require energy. Only moving against a force requires energy. E=F*D. A newton is force, but a newton-meter is energy. So the magnet on your refrigerator does not use energy, but energy is required to pull it off.
How is it obtained, stored, replenished?
Here is a really cool fact that you can use to impress chicks at cocktail parties: A magnetic force and an electrical force are the SAME THING. The only difference is your inertial frame of reference. Let's say you have two parallel copper wires with current flowing through them. The negative charge in the electrons and the positive charge in the copper nuclei should cancel each other out, and there should be no force between them. BUT THERE IS. This is magnetism. But it is really just plain only electrical attraction because the electrons are moving, so their inertial reference frame is different from the reference frame of the copper nuclei. A moving reference frame has a Lorentz contraction, so the copper nuclei "see" more electrons per length of wire, resulting in an attraction.