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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.
No, this is an elemental misunderstanding. Magnetism is inherent in the makeup of atoms, and thus of magnetic materials. Electrons have a negative charge and protons have a positive charge. As per Maxwell and the theory of Electromagnetism, electricity and magnetism are permanently and inextricably intertwined.
OK, so the "force" a magnet exerts is always sourced from outside the magnet itself. Therefore looking for an energy source inside the magnet is hopeless and useless; there is no internal energy source powering a magnet.
Imagine a magnet being attracted to a piece of metal. As they move together and within the effective range of the magnetic field, it looks like the magnet "pulls" the metal towards it, right? Wrong.
The only force involved was propelling the magnet and the metal towards each other, and that was an external force applied. But Wait you say! Once within the range of the magnetic field, the magnet still pulled the metal in, right? Still wrong. Those two objects began falling inwards towards their lowest common energy state. And that energy state is a property of, wait for it, the magnet and the piece of metal. It's an inherent materials property.
Think of it like this. The Earth has gravity, and gravity draws other objects in too, right? So what energy source drives gravity? And the answer is *nothing*. Gravity is an inherent property of mass. What draws objects with mass together is, those objects are falling towards their lowest common energy state.
Einstein actually said that gravity isn't a force, it's a warping of SpaceTime. Thus it is conceptually correct to think of gravitational attraction like falling to the bottom of a dent or hole in spacetime. This is tricky for us to imagine though, because in this view there is no "gravity" and there is no "force" pulling those objects down. What pulls them down is a universal desire for all matter to occupy the lowest possible energy state.
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.