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Permanent Magnetic Materials Without Rare Earth Metals

82 points by Breadmaker 8y ago

workingpatrick 8y ago
Link == Internal Server Error
SimonDorfman 8y ago
Page wasn’t loading for me. This archive.org link seems to work though: http://web.archive.org/web/20190408183112/http://www.diva-portal.org/smash/record.jsf?pid=diva2%3A1295906&dswid=3940 http://web.archive.org/web/20190408183112/http://www.diva-po...
philipkglass 8y ago
Of the papers based on this thesis work, this one has the most comparisons to other magnet families: "Directly obtained τ-phase MnAl, a high performance magnetic material for permanent magnets" https://www.sciencedirect.com/science/article/pii/S0022459616300548?via%3Dihub https://www.sciencedirect.com/science/article/pii/S002245961... These magnets aren't as strong (in terms of energy product) as those based on rare earth elements, but they are stronger than ferrite permanent magnets. They are also more tolerant of high temperatures than neodymium based magnets.
- leggomylibro 8y ago
  >They are also more tolerant of high temperatures than neodymium based magnets. Ooh, that's exciting. The nickel coatings on NdB magnets is nicely conductive, but they are difficult to solder to without destroying their magnetism. One neat trick is that neodymium magnets seem to tolerate extreme temperatures better if you cover as much of them as possible with slabs of ferrous metal during the time that they are at an elevated temperature.
pfdietz 8y ago
Whatever happened to iron nitride? That was supposed to be a promising alternate ferromagnetic material. EDIT: https://nironmagnetics.com/ https://nironmagnetics.com/
- danbr 8y ago
  I worked as an undergraduate in a academic research lab trying to develop this exact stuff. I would also hazard a guess that we were funded by the same ARPA grant as niron was. It was a cool concept and got me interested into materials science. Unfortunately the post doc didn’t seem to care too much and the work didn’t go anywhere. Neat stuff none the less.
stevespang 8y ago
Barking up the wrong tree, as they say. These compounds were already investigated by Ames labs few years back, ho hum results. There should be an all out "Manhattan project" on the Iron Nitride chemistry, it has over twice the energy product as Neo and it has many more times the intrinsic coercivity (resistance to demagnetization). This would bring about the next big revolution in magnet science and also deprive the Chinese of a strategic annoyance they have over the world in rare earths. At this moment I would say the Japanese lead the efforts to reduce rare earth dependence and have the most advanced magnetic chemistry research.

82 points by Breadmaker 8y ago

Link == Internal Server Error

Page wasn’t loading for me. This archive.org link seems to work though: http://web.archive.org/web/20190408183112/http://www.diva-portal.org/smash/record.jsf?pid=diva2%3A1295906&dswid=3940 http://web.archive.org/web/20190408183112/http://www.diva-po...

philipkglass 8y ago

Of the papers based on this thesis work, this one has the most comparisons to other magnet families: "Directly obtained τ-phase MnAl, a high performance magnetic material for permanent magnets" https://www.sciencedirect.com/science/article/pii/S0022459616300548?via%3Dihub https://www.sciencedirect.com/science/article/pii/S002245961... These magnets aren't as strong (in terms of energy product) as those based on rare earth elements, but they are stronger than ferrite permanent magnets. They are also more tolerant of high temperatures than neodymium based magnets.

leggomylibro 8y ago
>They are also more tolerant of high temperatures than neodymium based magnets. Ooh, that's exciting. The nickel coatings on NdB magnets is nicely conductive, but they are difficult to solder to without destroying their magnetism. One neat trick is that neodymium magnets seem to tolerate extreme temperatures better if you cover as much of them as possible with slabs of ferrous metal during the time that they are at an elevated temperature.

pfdietz 8y ago

Whatever happened to iron nitride? That was supposed to be a promising alternate ferromagnetic material. EDIT: https://nironmagnetics.com/ https://nironmagnetics.com/

danbr 8y ago
I worked as an undergraduate in a academic research lab trying to develop this exact stuff. I would also hazard a guess that we were funded by the same ARPA grant as niron was. It was a cool concept and got me interested into materials science. Unfortunately the post doc didn’t seem to care too much and the work didn’t go anywhere. Neat stuff none the less.

stevespang 8y ago

Barking up the wrong tree, as they say. These compounds were already investigated by Ames labs few years back, ho hum results. There should be an all out "Manhattan project" on the Iron Nitride chemistry, it has over twice the energy product as Neo and it has many more times the intrinsic coercivity (resistance to demagnetization). This would bring about the next big revolution in magnet science and also deprive the Chinese of a strategic annoyance they have over the world in rare earths. At this moment I would say the Japanese lead the efforts to reduce rare earth dependence and have the most advanced magnetic chemistry research.