
Iron Nitride Permanent Magnets – An Alternative to Rare Earth Magnets (2014) - peter_d_sherman
http://license.umn.edu/technologies/20120016_iron-nitride-permanent-magnet-alternative-to-rare-earth-and-neodymium-magnets
======
jwr
This is important, much more than most people think. You don't realize how
many things around you need strong magnets.

> This technology for producing iron nitride permanent magnets has been
> exclusively licensed.

Interesting — I wonder to whom.

~~~
VMG
I could come up with electrical motors and generators. Before that I saw them
for controlling the arm of spinning hard drives, and those aren't used that
much anymore. What else is there?

~~~
falsedan
> _spinning hard drives, and those aren 't used that much anymore_

Hey! Are you basing this statement on your own experience of your
personal/business hardware? Because spinning rust has never been more heavily
used, for bulk on/near-line storage.

Judging by the list of alumni from Prof. Wang's group, HDD manufacturers have
a strong demand for advanced applications of magnets, plus a tiny fraction
from biomedical techs.

[0]:
[http://www.nanospin.umn.edu/people-0](http://www.nanospin.umn.edu/people-0)

~~~
VMG
You were right, I did not consider bulk storage outside my personal use.
Thanks.

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sliken
"Theoretical limit of its magnetic properties are more than twice the maximum
reported magnetic energy product for a rare earth magnet"

Call me a pessimist, but if the theoretical is more than twice the actual for
rare earths that means the new magnet might well be weaker than the old ... in
reality.

It's doubly suspicious that they don't mention the theoretical vs reality for
the rare earths.

~~~
wbhart
The theoretical maximum for a neodymium magnet is grade N64, i.e. 64 Mega-
Gauss Oersted.

~~~
emj
Hmmm, from the summary: "The theoretical magnetic energy product for this iron
nitride (Fe16N2) magnet is 130 mega gauss oersteds"

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leggomylibro
Thank christ, have you tried to source NdB magnets at quantity lately? I hope
these get to be produced at scale soon, although unfortunately it sounds like
the technology has been "exclusively licensed," which in my experience means a
500% markup from whatever its aiming to supplant once it finally hits
production. The price of progress, I guess.

But yeah, I tried to order a few hundred rare earth magnets from China (where
almost all of the world's rare earth metals come from) and got told that they
can't export "pill-shaped" objects...bullshit, that's the same mealy-mouthed
politically-backed excuse that they gave for not shipping a few dozen CCP
badges through customs.

Anyways, the patent application doesn't make it sound THAT hard. Maybe it's
something you could DIY for personal use:
[https://google.com/patents/US20140299810](https://google.com/patents/US20140299810)

Maybe someone who knows more about...all of this...can correct me, but tl;dr:
Take an iron wire or sheet of diameter/thickness ~10μm-1mm. Strain it by
pulling it in opposite directions, e.g. using two rollers pulling in opposite
directions. While the iron is strained, heat it to ~125-600C in an atmosphere
of N2 or N2+inert gas at ~0.15-1.5 Pascals for 2-10 hours. You actually need
atomic Nitrogen and this part of the patent is vague, but I think ~500C might
be enough to break the N2 bonds? They also describe a urea infusion process,
but that sounds more difficult for a garage effort. Anyways, if that all
works, it sounds like you can stack 'em to make larger and more powerful
magnets. Anyone up for it?

~~~
raziel2701
There's a lot of canceled items in the patent, I wonder if that's because it
was too vague to be part of the patent? I agree with your interpretation of
the manufacturing process. They expose the sheet of <001> Fe to either
nitrogen gas (N2) or NH3. NH3 does break apart with high temperature but
ideally you want to work with N2 instead for safety reasons. It's more
efficient to break the N2 bond using a cracking source, they use a plasma arc
to break the bond of N2.

The usual problem is always going to be compositional control, you know,
coming up with a method that preserves the rather excessive stoichiometry of
Fe16N2. There's a bunch of other phases that can be achieved with simpler
stoichiometries, so the long term stability of this magnetic phase is of
concern to me. What are the ideal operating conditions of this magnet before
interdiffusion occurs and we lose the right stoichiometry? Maybe there's a
small window that could render this material inapplicable to many mechanical
or thermal conditions.

Oxidation of the Fe sheet before nitridization is another concerns. Fe
oxidizes very easily and would become a barrier for the nitrogen.

The other concern is that they characterize the magnet's performance only on
the product of saturation magnetization and coercivity, and mention using ion
bombardment to enhance the coercivity. This can be interpreted to mean that
the Fe16N2 has a poor coercivity which means that it's a magnet that is very
easy to switch with weak magnetic fields or thermal energy. Not what you want
for permanent magnet applications.

So I still have a lot of questions and concerns although I do think it's worth
pursuing this material because it makes a lot of financial sense as Fe and N
are super common and easier to process.

------
markvdb
[http://www.designworldonline.com/coming-revolution-high-
stre...](http://www.designworldonline.com/coming-revolution-high-strength-
magnets) (December 2014) seems to give a wider overview of non-rare earth
magnet development: FeN, MnBi, Ce and exchange spring magnets.

------
nickcw
Here is an article with a bit more info about Iron Nitride (it has quotes from
Professor Jian-Ping Wang who is cited in the original link).

[https://www.electronicsweekly.com/news/research-news/rare-
ea...](https://www.electronicsweekly.com/news/research-news/rare-earth-free-
magnet-made-from-cheap-materials-2016-05/)

Looks like there is a way to go before commercialization, but then that
article was written in May 2016 so maybe they've improved the process since
then.

> It is only a tiny sample, a film 500nm thick, but it is the real thing.

~~~
glenneroo
According to the patent application[0] it's from 2012.

[0][https://www.google.com/patents/US20140299810](https://www.google.com/patents/US20140299810)

------
ridgeguy
Some important applications properties I didn't see listed in the brief UofM
blurb:

Curie temperature: - at what temperature do these magnets start to lose their
magnetic energy?

Coercivity: - how easily are these magnets demagnetized by external energy
input (vibration, inductive kickback from motor windings, transformers, etc.)?

------
zeristor
This looks to be up an update from several months ago, with graphs and data.

However the text is very domain specific, I can't follow it myself:

[http://www.nanospin.umn.edu/new-magnetic-
materials](http://www.nanospin.umn.edu/new-magnetic-materials)

~~~
castratikron
They use the term "giant saturation magnetization" to describe an iron nitride
magnet that they made. The saturation magnetization is the point where the
magnetization in a material cannot increase any further. Think of it like a
maximum strength of a magnet. Neodymium magnets have their saturation
magnetization around 1 Tesla, and they reported that their iron nitride magnet
has a saturation point at 2.68 Tesla, so it's greater. (The magnetics
community likes putting words such as "giant", "colossal", and "extraordinary"
in front of terms to emphasize how big something is. Especially when it comes
to magnetoresistance)

BH max is a characteristic of a magnetic material. You can think of it as a
kind of magnetic energy density rating, so more is better. What you linked to
showed that the iron nitride magnet they made had a BH max similar to a
neodymium magnet.

Also, I love the name "Minnealloy". Very Minnesotan.

------
batushka
I love how US beats foreign cartels or shortages by true technology (fracking,
magnets).

~~~
acchow
This isn't just an American thing.

~~~
jessaustin
Perhaps, but we don't love it when others do this.

~~~
logfromblammo
Sure we do. They just become naturalized Americans if we can get our hooks
into them, and honorary Americans if we can't. America loves being the sewer
for everyone else's brain drains.

Just look at great Americans like Nikola Tesla, Albert Einstein, Werner von
Braun, Leo Szilard, Alexander Graham Bell, William J. Kroll, Alexey Pajitnov,
Igor Sikorsky, etc.

------
creeble
Interesting to note that this[0] article from Magnetics Magazine in 2016 has
exactly zero mention of FeN magnets.

Vapor?

[0] [http://www.magneticsmagazine.com/main/articles/permanent-
mag...](http://www.magneticsmagazine.com/main/articles/permanent-magnets-in-a-
changing-world-market/)

------
raverbashing
Science beats scarce natural resources. Again

~~~
sangnoir
Call me when science transmogrifies base metals into gold for less than it
costs to dig the stuff up from the ground: humanity has been trying since
before science/ when science _was_ alchemy.

~~~
Robotbeat
Gold sucks compared to aluminum and other metals for most uses. Aluminum used
to be way more expensive than gold. And when science was "alchemy" aluminum
metal wasn't even known. It wasn't produced until the 19th Century, and at
first absurdly expensive.

And we can, of course, transmute lead into gold using science. It's expensive
and pointless, of course. And gold itself is mostly valued for its rarity and
shininess.

But we can transmute carbon into diamond for less than the market price for
diamonds. Diamonds are more expensive than gold.

------
usmeteora
This is interesting. I am an Electrical Power Engineer, and at my tech school,
our Senior Thesis projects are essentially real Engineering firms coming to
the school and assigning a group of engineers to work on a project they are
actually working on in real life.

The company I worked under makes electric motors for navy ships and other
government contracts. There are enormous machines in side of these things, but
rare earth metals are economically volatile, on a scale unlike most other
industries.

China and Malaysia have most of the rare earth metal mines (we had a bastanite
mine in CA where you can mine for rare most of the rare earth metals, but the
liberals did not want the pollution in California, so as a result, they closed
down the mine (before it reopened for a bit and then went into Chapter 11
bankruptcy last year) and made America dependent on rare earth metals from
Asia, where for a long time, and probably still now, they have zero emissions
policies so we are effectively polluting the planet more (but not in my
backyard so it feels good to feel clean and drive a prius as long as all the
rare earth metals and pollution caused mining it are done by people working
1/26th the pay in China breathing in that air in not me, it makes me feel
green), until Elon Musk has recently come and been working with mining
companies in the U.S. for his operations.

At the time in 2011 when I was a senior working on this project and the
explicit motivation for investing in research for this, China had overnight
banned global trade on rare earth metals with 24hrs notice for 6months, to
focus on their internal development, skyrocketing the price of 90% of the
worlds rare earth metal production by over 9000%

At that time, my engineering group was contracted to come up do motor design
and look for utilizing either less rare earth metals while meeting the same
specifications for output or looking up for alternative metals.

We ended with a form of a Halbach array, which arranges rotor and stator
magnets in a permutation of an orientation where the magnetic field is
increased on one side and cancelled on the other, reducing the amount of loss
not going into the relationship between the stator and the rotor and
increasing the magnetic field where it did.

There is still a lot of need for this kind of design and optimization, and I
ended up in a different niche of Electrical Power but, people were and are
dishing out alot of money around this kind of work for good reason.

I looked up patents a few years after I graduated around this kind of thing
and they have spiked up significantly in the passed few years, particularly
with halbach arrays.

And you are right, most people don't realize rare earth metals are required in
electric motors, wind turbines, inverters for solar panels and most movements
we associate with sustainable energy, despite the fundamental components being
extremely rare economically volatile, and relatively no innovation going on in
the space of addressing these issues.

~~~
flyinghamster
> but the liberals did not want the pollution in California, so as a result,
> they closed down the mine (before it reopened for a bit and then went into
> Chapter 11 bankruptcy last year)

Oh, so it was the fault of liberals, and not of dumping by China? That's news
to me.

Besides, Tesla Motors has shown that the good old AC induction motor, which
uses such rare materials as copper, iron, and aluminum, works quite nicely as
an automotive drive motor. You seem to be conflating lithium mining with rare
earths here.

~~~
tkahnoski
'liberal' sounds like over-generalization that's common today.

'environmentalist' would have been a more specific political label.

~~~
usmeteora
I didn't say all liberals, I said liberals. I'm not sure there were any
republicans apart of this but there could have been.

I concede this to you, I should not over generalize. I don't identify entirely
with either and being assumed to be one or the other is annoying but more
importantly degrading society as a whole with these increasingly polarizing
and decreasingly diverse categorizations.

------
novalis78
First thought 'no way!' \- neodymium magnets had a huge impact on electronics
and mechanical systems... and then twice the strength? Incredible!

~~~
ptero
As another poster said, iron's _theoretical_ max is twice the _currently_
available rare earth strength. It's apples and oranges.

~~~
Sean1708
From a quick google search it does indeed look like the theoretical BHmax of
rare-earth magnets is about 60 MGOe, so I think that might just be poor
wording from the article. That said, I would agree that we should be waiting
to sing their praises until they can beat rare-earth magnets in practice.

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panzer_wyrm
As a bonus - this is as environmentally friendly and cheap as they come.

We have a lot of both fe an ni.

~~~
gruturo
> We have a lot of both fe an ni.

Nitpick - "Ni" stands for Nickel. The magnets described in the article are
Iron Nitride - that means Iron and Nitrogen (Fe16N2), not Iron and Nickel.

Your point stands - Nitrogen is extremely abundant.

~~~
logfromblammo
Both of those are actually common enough that if a biological ecosystem ever
discovered a competitive advantage for very powerful magnetic crystals, it
might have come up with Fe16N2 instead of just the magnetite (Fe3O4) and
greigite (Fe3S4) that currently form the basis of biological magnetism.

[https://en.wikipedia.org/wiki/Magnetosome](https://en.wikipedia.org/wiki/Magnetosome)

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stillhere
It's a miracle. How do they work?

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MertsA
Can we get a [2012] on the title?

~~~
creeble
Title has apparently been changed to 2014.

Has anything come of this revolutionary creation since? I.e., any actual
magnets in production?

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oldandtired
Goes to show that stupidity isn't dead. I wonder what kind of "licensing fees"
will they require? I also wonder how much of this research was paid for by
public money?

Instead of making this available to everyone so that these kinds of magnets
can get out there, they want to scrooge first. If I recall correctly,
universities that have gone down this path have simply stalled the progress of
mankind instead of pushing it forward.

~~~
panzer_wyrm
If public money went into development - the public is definitely entitled to a
cut.

~~~
smaddox
The US government typically gets non-exclusive license rights to any patents
developed under US grants.

