The Japanese learned how to make L1₀-FeNi magnet without rare earth metals in just 300 hours



    Since the 60s it has been known that a meteorite alloy of iron and nickel in an extremely equilibrium state has magnetic properties. But chemists still have not been able to recreate in laboratory conditions the same ideal atomically ordered phase L1 0 -FeNi. The reason is that in cosmic bodies L1 0 forms over hundreds of millions or billions of years, and we live on a different time scale, unfortunately. But now the problem is finally resolved.

    Researchers at Tohoku University have managed to reduce the duration of a chemical reaction from hundreds of millions of years to less than 300 hours. A university press release calls this a “time machine journey,” when years “scroll” in fast forward. In scientific workthe authors explain that the ordered phase of the alloy is achieved due to three factors associated with the liquid state of metals: 1) high diffusion rates of composite elements at lower temperatures during crystallization; 2) a large driving force during precipitation of the precipitate in the form of a solid phase L1 0 ; 3) the possible presence of clusters L1 0 .

    The magnet is manufactured by annealing the Fe 42 Ni 41.3 Si 8 B 4 P 4 Cu 0.7 ribbon for 288 hours at a temperature of 400ºC. The result is a structure, as in meteorites.



    The switching of magnetization after a phase transition at the second Curie point of 700-750ºC occurs in a magnetic field with a voltage of at least 3.5 kiloersteds.



    The results of scientific work are extremely important for modern industry. High-quality magnets made of iron and nickel alloys are widely used in automobiles, household appliances, medical equipment, etc. Until now, the manufacture of such magnets has required the use of rare earth metals such as samarium, neodymium, dysprosium.

    “Although such magnets were invented in Japan, the issue of the import of rare-earth metals has become too political,” the press release said. “Now it has become extremely difficult for Japan to maintain industrial superiority and competitiveness in the production of energy-saving technologies for next-generation electric cars / devices.”

    World reserves of rare earth metals are limited, and most are concentrated in China. It controls 95% of the world market , and recently imposed export restrictions, which is in earnest aroused all.

    If there are no deposits in the country, and the Chinese behave strangely, you have to be creative.

    Although the Japanese invented a magnet for their own industry, everyone else can take advantage of their labor, especially since environmental restrictions in many other countries promote similar restrictions on the import of rare earth metals. The scientific work describing the technical process (production is being carried out on the same conventional equipment as the production of ordinary magnets with rare earth metals) is in the public domain .

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