Carbon Magnets At Room Temperature

Bolie writes: "Trying to make high temperature super conductors yielded an unexpected result. The pure carbon bucky ball material was put under pressure to make sheets. That worked. Picture microscopic bubble pack. But the result was a sheet that was magnetic at room temperature. It has not escaped the attention of the discoverer, Tatiana Makarova, that this might be useful for a non-metallic computer memory. The material is also lighter than metals, flexible and transparent. Lasers anyone?"

Curie Point

[Self Bias Resistor]

Actually, no. What the article was saying was that the material is the first non-metallic material that was magnetic at room temperature (meaning that other non-magnetic materials weren't, at least not at room temperature). The point about the material being magnetic even above 200C was about the material's Curie point (above which the material stops being magnetic) being much higher than any other material, the previous record being 255C which was held by a different form of buckyballs. So this material is interesting because it's the first non-metallic material to be magnetic at room temperature and has a higher Curie point than any other non-metallic material to date.

Apparently, the material's magnetism could be linked to unpaired electrons, which can sustain a magnetic field when their spins are aligned (in this case there are unpaired electrons). One possibility is that they bond in triangular groups of three, which would provide for unpaired spins.

Although, to be used as computer memory it would have to have uniform magnetism, not just in pockets. But either way it's a significant step forward.

Re:250 degrees ? 200 ?

[TheMidget]

The new magnetic sheet "...is the first non-metallic magnet to work at room temperature."

"...she found instead that the new material was magnetic even above 200 C. Until now, the highest temperature at which a non-metallic material was magnetic was 255 C."

Ok, let's take it word after word:

• room temperature.: Aound 21C.
• the new material was magnetic even above 200 C..The word "even" seems to imply that it is a feat to go above a certain temperature . Which implies that with higher temperature, materials tend to lose their magnetism (Curie point). Which implies that the material is also magnetic for all temperatures below 200 C. Which includes 21C, i.e. room temperature. Probably, the reason for the strange formulation was that the researcher didn't have any oven handy which went over 200 C, or that any higher temperature fried his magnetism measuring equipment, or whatever. So he was just saying that at 200 C it was keeping its magnetism, and that it was likely that it would keep it even beyond that mark.
• Until now, the highest temperature at which a non-metallic material was magnetic was 255 C. The words "until now" means "all materials known before" this one was discovered. Meaning that the 255 C refers to a different material. Oh, and btw, 255 C (that's minus 255) is below room temperature.

So where is the contradiction?

Re:minus signs

[TheMidget]

Or maybe, his browser doesn't show the minus sign. Due to a bug, some early versions of konqueror did that with certain fonts...

Re:minus signs

[bowb]

yes, that's what is happening. IE5.5 isn't showing the minus sign on -255 even though it's there in the source. That's pretty scarey.

mystery solved

[bowb]

They used a Soft Hyphen (­ or ­) character instead of a minus sign. Browsers are not supposed to display a Soft Hyphen unless the line is broken at that point.

Buckyballs are wonderful...

[ymgve]

Not only will they give us a new form of storage, but they can also be used as a treatment for AIDS [wired.com].
Interesting how versatile a simple molecule can be..

Re:Buckyballs

[nealbutler]

Here's a few interesting links on the subject...

• Here [insite.com.br] is a not-too-technical report on buckyballs, their properties, etc.

• Pretty pictures!!! [fsu.edu]

• According to
• this article [physicsweb.org], buckyballs hold the record for highest-temperature superconductor.

• A report [ameslab.gov] (fairly technical) on research into building buckballs...

• And
• here's [lbl.gov] a report on single buckyball transistors.

Enjoy! :)

Re:250 degrees ? 200 ?

[PhilHibbs]

It's a mistake in the HTML, the 250 should be -250, but they put a soft hyphen in instead of a minus sign or a dash.

Re:Fast writes, slow reads?

[wyldeling]

By writing to a particular memory cell, light passing through that location may be polarized differently because of the different magnetic field. This could then be used to verify the particular state it is in. This could be a very fast way to read the memory.

Re:Fast writes, slow reads?

[jeff_bond]

You can read the thing with a magnetic head.

I believe minidiscs work like this. Someone's bound to correct me if i'm wrong.

To write, the laser heats a very small spot on the disc (to above the Curie point), and the magnetic head magnetises the spot in the required orientation. The use of the laser allows a much smaller spot on the disc to be targetted than with the magnetic head alone.

Reading is done without the laser, just the magnetic head in a manner similar to a hard disc.

Jeff

Re: no, and here's why, and why this matters

[phoenix_orb]

No, -255C is impossible. It is below absolute zero. (-253.15C or 0Kelvin)

I would also conclude that they may have goten Kelvin and Celsius mixed up. (A lot of places do.)

I did some projects on this way back when cutting edge was Yittrium-Barium-Copper Oxide and we could use Liquid nitrogen rather than Liquid Helium.

Just think of the possibility of superconductivity at room tempurature:

Batteries that have huge spans. (You make a superconductor into a ring... walla.. you made a battery.)

Computers with no heat dissapation, and super fast. (Superconductors don't release ANY energy as waste, so no melting down of processors because they don't get hot at all. If the material is robust enough, they could make the MoBo, video card, and Ram. Damn, I bet that would make a quick computer )

Anyway, this discovery is important, as it one step closer to this utopia.

http://www.egglescliffe.org.uk/physics/supercond /b ob.html ( an intro to superconductivity ) Will give you a primer if you are interested in this.

Re:Fast writes, slow reads?

[Anonymous Coward]

If you change the permitivity of the magnetic material (i.e. magnetic resistance)then there is a simple equation that says for a given frequency ( i.e. a laser has frequency) there will be a slight phase shift. This phase shift is what one detects to be a one or zero. Now if the permitivity can be varied, then you get varying phase shifts, giving one the capability to store multiple bits in one location by detecting this phase shift. The sheet material could be used like a phased-array radar such that the total square area is in lock-step and performs a scanning function. This scanning function forms a beam that scans another sheet of the same material, but this other material is storing the actual memory bits. When the beam hits a certain point on this sheet, the bit (one or zero) creates a spike to appear in the sheet of material acting like the radar. This signal then can be amplified to let one read the memory. The same technique could be used with lasers doing the scanning to erase the other materials bits. One could also use a MEM scanning beam (see the HDTV technique) of the sheet material to read or set the data bits.

It has been awhile since I worked in this area, but this is what is done for phased-array radars whereby they apply a voltage to each phased-array element. This voltage controls the degree of permitivity and when an RF frequency is sent through the material, a fixed phase shift is produced. All the elements working in concert (with the same phase shift) gives the radar its beam. By rapidly varying the permitivity for a given frequency, varying phase shifts are produced thus giving the impression the beam is sweeping across space.

Re:Curie Point

[Phrogz]

The point about the material being magnetic even above 200C [...] the previous record being 255C which was held by a different form of buckyballs...

You do realize that the HTML for the article is broken, and that the previous record was -255C, right? Because simple math states that +255 is already greater than +200, right?

Re:The shape of a bucky ball...

[Blorgo]

(Ignoring the fact that most of the world calls the sport the Americans call soccer 'football'; I'll write with American usage:)

Right, and wrong. Buckballs are C-60 and soccerball shaped, but some relatives are indeed football shaped (more like a rugby ball, really), and have 70 or 76 Carbon atoms inside.

"C60 and C70 have similar properties, with six reversible, one electron reductions to C60(6-) and C70(6-) having been observed, whereas oxidation is irreversible. The first reduction for both fullerenes is ~1.0 V (Fc/Fc+), indicating they have electron accepting properties. C76 exhibits both electron donor/acceptor properties. C60 has a tendency of avoiding having double bonds within the pentagonal rings which makes electron delocalisation poor, and results in the fact that C60 is not "superaromatic". C60 behaves very much like an electron deficient alkene and readily reacts with electron rich species. " (from
http://www.bris.ac.uk/Depts/Chemistry/MOTM/bucky ba ll/c60a.htm )

You have no idea what you are talking about.

[mindstrm]

Absolute zero is -273.15C (or is it .16)
or 0K There is no such thing as 'degrees kelvin'; the proper way to say it is 'zero kelvins'.

And this discovery has absolutely nothing to do with superconductivity; only that they were trying to produce a superconductor when they discovered it was magnetic. This is not an advancement in superconductivity. They didn't produce a superconductor. That's obvious even without reading the article...

Also, you are correct about superconductors.. but... the reason microprocessors work is because they are full of SEMIconductors... transistors... you HAVE to have resistance.. you can't build logic with pure superconductors.

Re:You have no idea what you are talking about.

[Fyndo]

Errr. there are superconducting devices that you can use to build logic. Well, you need insulators too, but the josephon junction can be used as a switch, and involves no semiconductors. That said, it's not something we'll be seeing any time soon.

Re:Forget about Laser Memory....

[FFFish]

What about Spherical Magnets [leevalley.com]?

Pretty cool. Now if I could only think of a use for them... :)

ITS -255c

[geekoid]

There is a bug in some browsers that fail to display the - sign. The articl may appear to say the previous temp was 255c when it actually says(look in the source) -255c.
I don't know how to post a story update, so I'll do this here.

Re:The shape of a bucky ball...

[Hal-9001]

Actually, that shape is technically called a truncated icosahedron, IIRC. That way it doesn't matter what sport you play: everyone is equally confused... ;-)