Go back
graphene magnet?

graphene magnet?

Science

Clock
Vote Up
Vote Down

In theory, it might be possible to make a pure graphene magnet!

https://phys.org/news/2020-05-unraveling-magnetism-graphene-triangular-flake.html

But would it ever be possible to make such a pure graphene magnet with anything like the same magnetic field strength of the current magnets? Or would any pure graphene magnet necessarily be only very weakly magnetic and thus have only very limited application?

Clock
Vote Up
Vote Down

@humy
Here is another related piece, but not these triangular shapes, just regular graphene.

https://phys.org/news/2013-05-magnetic-graphene-revolutionise-electronics.html

Clock
Vote Up
Vote Down

@humy said
In theory, it might be possible to make a pure graphene magnet!

https://phys.org/news/2020-05-unraveling-magnetism-graphene-triangular-flake.html

But would it ever be possible to make such a pure graphene magnet with anything like the same magnetic field strength of the current magnets? Or would any pure graphene magnet necessarily be only very weakly magnetic and thus have only very limited application?
Great science!

But not a useful technology in any conceivable way today.

* You need to make the triangular flake (and we talk nanometers here, so you have to arrange single atoms if you want to see the effect).
* you have to stay in ultra-high vacuum (the magnetic state is destroxed if you pair the electrons in a chemical bond).
* you get a net spin of 1 for the whole arrangement. (Kudos to the guys who actually managed to measure this!)

But hey if we understand better how magnetic effects work it might lead to technological advance.

Clock
Vote Up
Vote Down

@Ponderable
I wonder what they call 'ultra' vacuum? My sputtering tools get down to 7E-8 with just one cryopump.
My ion implanters I used to service had 3 big cryopumps and regularly got into the 8 range.
Is that called ultra? Not sure what level they are talking about.
That is still what, 6 orders of magnitude dirtier than the outside of the ISS or the surface of the moon.
I often thought about the idea of building ion implanters on the moon or anything else needing high vacuum levels.
more than half the weight of an ion implanter or sputtering tool or ion etcher or electron microscope and the like is the SS frame to hold off atmosphere.
So on the moon, just lay out the physics needed for the job, microscope, molecular beams, ion etchers, whatever, instant vacuum😉

Clock
Vote Up
Vote Down

@sonhouse said
@Ponderable
I wonder what they call 'ultra' vacuum? My sputtering tools get down to 7E-8 with just one cryopump.
My ion implanters I used to service had 3 big cryopumps and regularly got into the 8 range.
Is that called ultra? Not sure what level they are talking about.
That is still what, 6 orders of magnitude dirtier than the outside of the ISS or the surface of the ...[text shortened]... the physics needed for the job, microscope, molecular beams, ion etchers, whatever, instant vacuum😉
I think an "ultra vacuum" is pure journalist speak.

Clock
Vote Up
Vote Down

@deepthought said
I think an "ultra vacuum" is pure journalist speak.
It is "Ultra high vacuum" and that is defined at least in Germany as below 10e-5 Pa.

The Point to reach so low pressures is to make sure that there is as few foreign molecules around as possible.

In the case of the investigated graphene flake the effect is from having unpaired electrons, thso would imidiately pair if given half a chance.

Clock
Vote Up
Vote Down

@Ponderable
Also the lengthening of the free mean path of molecules.

Clock
Vote Up
Vote Down

@Ponderable
I wouldn't think CERN folks would say 750 odd microns of pressure would be 'ultra vacuum'😉. 10E-5 pascal is 0.00075 torr, I would not be able to run either the ion etcher, sputtering tool or ion implanter with that poor a vacuum level.

Clock
Vote Up
Vote Down

@sonhouse said
@Ponderable
I wouldn't think CERN folks would say 750 odd microns of pressure would be 'ultra vacuum'😉. 10E-5 pascal is 0.00075 torr, I would not be able to run either the ion etcher, sputtering tool or ion implanter with that poor a vacuum level.
It is just as it is defined in ISO 3529-1:2019

And I think there is a mistake in your formula 1 Pa is 0.0075006375541921 Torr
If I go to 10E-5 Pa I am at 0.000000075 torr.
And a lot of sputtering equipment is running at 10E-4 Pa in our lab...

The next level is called

Clock
Vote Up
Vote Down

@Ponderable
Ok, that looks like 7.5E-6, torr. Does that look right? If so we cannot run at that level, we get 100 times lower, 7.5E-8 torr. Is there a way to get scientific notation for these converters?

Clock
Vote Up
Vote Down

@sonhouse said
@Ponderable
Ok, that looks like 7.5E-6, torr. Does that look right? If so we cannot run at that level, we get 100 times lower, 7.5E-8 torr. Is there a way to get scientific notation for these converters?
Actually it is 7.e-8 as in your lab.

Cookies help us deliver our Services. By using our Services or clicking I agree, you agree to our use of cookies. Learn More.