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Print 31 comment(s) - last by Trippytiger.. on May 24 at 1:34 AM

Room temperature superconducting? No problem - at 21,000,000,000 pascals.

Superconducting materials are themselves not exactly rare in the modern age. A great deal of research has been put into developing better superconductors in the search for the elusive room-temperature superconducting material. Why are scientists working so diligently towards this fabled matter? One of the so-called high-temperature superconducting materials with the highest known Tc, or critical temperature is a ceramic material composed of thallium, mercury, copper, barium, calcium, strontium and oxygen -- it reaches this point at a record setting 138 degrees Kelvin (-211.27 Fahrenheit).

While this is arguably better than the first discovered superconductors, which switched states at around 20 K (-423 F), it still prevents superconductors from finding their way into household electronics and large scale power systems, just to name a few, where their presence would revolutionize their respective industries entirely.

Researchers at the Carnegie Institute of Science and Stanford University are looking in another direction to study the mystery of the superconducting state. The group has been observing what happens to superconductors above their Tc when under extreme pressures. They used a bismuth-based cuprate, or ceramic copper oxide, which many high-temperature superconductors are based on, and studied the changes the matter underwent as pressure increased. Their observations will be published in the May 30th issue of Physical Review Letters.

"Pressure has the added bonus that it can be applied gradually, like tuning a radio. We gradually tuned in to the superconductivity and could watch what happened over a broad range of pressures," explains one of the paper's co-authors, Alexander Goncharov of Carnegie's Geophysical Laboratory. Using a diamond anvil, the group brought the test samples up to a pressure of 35 Gigapascals, or 350,000 times atmospheric pressure at sea level. Using Raman spectroscopy and X-ray diffraction to measure the changes in the sample as it underwent pressurization, they found that the sample's state switched to superconducting at around 21 GPa.

While it's highly unlikely that electronic appliances will soon feature high-pressure circuitry, the group's work opens new doors into superconductivity research. Studying the interaction of the materials at the atomic level while under pressure may provide insight into how scientists can tweak new materials to achieve even higher Tcs and work towards bringing the still mythical room-temperature superconductor to life.



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Inarguably better...
By jtemplin on 5/21/2008 11:29:55 AM , Rating: 3
quote:
it reaches this point at a record setting 138 degrees Kelvin
quote:
While this is arguably better than the first discovered superconductors, which switched states at around 20 K


I disagree with this sentiment. It isn't arguable. Isn't the title of this article about high temp superconducting (yes it is, because that is the weakness that most needs research and improvement ). I am a firm believer in gradualism (as opposed to punctuated equilibrium-type thinking). So denigrating an improvement on the basis that it is small and won't revolutionize whole industries is slightly rediculous.
quote:
it still prevents superconductors from finding their way into household electronics and large scale power systems
I believe change (usually) happens slowly over many small steps. Once in a while there are breakthoughs and paradigm shifts (see writings of Thomas Kuhn, Structure of Scientific Revolutions) That is the biggest problem and the higher the temperature you can achieve this state, the less exotic cooling is needed, which has obvious benefits for wide scale adoption of superconduction.




RE: Inarguably better...
By jtemplin on 5/21/2008 11:42:00 AM , Rating: 2
Arg accidently hit post instead of preview...

Anyway I was just nitpicking I guess but such change is inarguably good! One of the big advancements in high(er) temp superconducting was getting materials to exhibit superconduction above the boiling point of helium, ~77 K.


RE: Inarguably better...
By Jimbo1234 on 5/21/2008 2:12:20 PM , Rating: 2
You mean the boiling point of nitrogen. Helium boils at ~4. One of the compressed gas helium cryo-coolers I use goes down to 4K. You can also get colder using a Joule-Thomson cooler. That will go down to ~1.4K

And on the note of temperature scales, why hasn't anyone mentioned the Rankine scale? I guess no one has had the pleasure of taking any thermodynamics courses.


RE: Inarguably better...
By masher2 (blog) on 5/21/2008 2:57:39 PM , Rating: 3
I believe the Rankine scale is only a topic in a few in a few engineering classes...certainly none of my physics-based thermodynamics courses touched upon it.


RE: Inarguably better...
By ImSpartacus on 5/21/2008 3:16:55 PM , Rating: 2
If you are going to use an absolute scale, you may as well use the one closest to Centigrade for scientific consistency's sake. Unless you're doing a lot in Fahrenheit, Rankine isn't worth bothering with.

I have never been taught to use Rankine. The only reason people still use Fahrenheit at all is because it is deeply ingrained in American culture.


RE: Inarguably better...
By jtemplin on 5/21/2008 7:39:44 PM , Rating: 2
Proof reading is for suckers... =D Thanks for the catch


RE: Inarguably better...
By Trippytiger on 5/24/2008 1:30:32 AM , Rating: 2
I have had the pleasure of taking several thermodynamics classes. The only way I learned about the Rankine scale is when I stumbled across the Imperial unit steam charts at the back of my thermo textbook, and it confused the hell out of me at first.

Frankly, I'm glad none of my professors tried to teach thermo in Imperial units. The less time we spend prolonging the lifespan of obsolete measurement systems, the better.


Actually....
By JasonMick (blog) on 5/21/2008 10:13:29 AM , Rating: 2
Levi, I don't know absolutely if this is accurate (as in I haven't verified it myself ;) ) but Superconductor.org reported that they achieved a new record using:
(Sn1.0Pb0.5In0.5)Ba4Tm5Cu7O20 on March 8. This new superconductor on eight independent trials averaged a TC, or critical superconducting temperature, of 185.6 K.

http://www.dailytech.com/Retraction+Room+Temperatu...

Again, in my own experience writing articles on superconductors/researching online, the numbers for the current "record" performers are very scattered and generally do not agree. However, if this record indeed holds up it would be significant as it would be the first non-pressurized ambient temperature superconductor (@ a temperature which occured naturally on Earth @ some time...)

Anyways nice article and cool stuff!




RE: Actually....
By MatthiasF on 5/21/2008 11:32:20 AM , Rating: 2
While it's not breaking any records, it's still interesting news in respect to pressure being important to the superconductivity.

As mentioned in the article, the researchers used a common base superconducting material to run the tests. I'm assuming that pressure would also help on any superconductor based on cuprates, and perhaps even other superconducting materials.

So, it invites revisiting dud materials by applying variable pressure ranges.


small detail but..
By agris on 5/21/2008 2:10:11 PM , Rating: 3
I don't think kelvin is measured in degrees. From wikipedia:

"The omission of "degree" indicates that it is not relative to an arbitrary reference point such as the Celsius and Fahrenheit scales, but rather an absolute unit of measure which can be manipulated algebraically (e.g. multiply by two to indicate twice the amount of heat)."




Please use Celsius
By eea on 5/22/2008 9:15:24 AM , Rating: 2
It seems like the posters here have never had a job in industry! Rankine is used and is a absolute scale like kelvin. If your calculations use pounds for mass flow, Rankine follows.




please use Celsius
By Urbanmech on 5/21/08, Rating: -1
RE: please use Celsius
By Crucial on 5/21/2008 10:09:51 AM , Rating: 2
Did someone call the whaaaaaaambulance?


RE: please use Celsius
By FingerMeElmo87 on 5/21/2008 11:10:22 AM , Rating: 5
yeah, he definitely needs a Manpon for his acking mangina


RE: please use Celsius
By ChiefsLead on 5/21/2008 1:18:58 PM , Rating: 2
Very well put!


RE: please use Celsius
By rtrski on 5/21/2008 10:11:14 AM , Rating: 5
K to C is a pretty easy conversion. Most people can do it in their head.

K to F is a little less direct, so personally I think writing the article in K and offering F as a convenience conversion was spot-on.

Disclaimer: yes, I'm American. Feel free to bash me now for my cultural imperialism....


RE: please use Celsius
By b2386 on 5/21/2008 10:12:01 AM , Rating: 2
Are you too lazy to simply subtract 273 from the Kelvin temp?


RE: please use Celsius
By amanojaku on 5/21/2008 10:14:51 AM , Rating: 3
quote:
Please dont post temperature in Fahrenheit. The rest of the world uses Celsius.


If everyone on this site is as technical as they claim to be they should be capable of converting from one to the other. Seriously, this is middle school mathematics, people.

°F = °C × 9/5 + 32
°C = (°F - 32) × 5/9
K = °C + 273.15
°C = K - 273.15


RE: please use Celsius
By Mitch101 on 5/21/2008 10:16:10 AM , Rating: 2
"The rest"

Can you provide all articles in Spanish too while your at it?

;)


RE: please use Celsius
By amanojaku on 5/21/2008 10:21:37 AM , Rating: 4
Urbanmech's comment was wrong. MOST of the world uses Celsius. Displaying Fahrenheit is like displaying Spanish.

And I'm an American saying this. I'm gonna get modded down...


RE: please use Celsius
By Urbanmech on 5/21/08, Rating: -1
RE: please use Celsius
By DanoruX on 5/21/2008 11:06:56 AM , Rating: 2
He's right, I have yet to come across a country other than the United States that still uses Fahrenheit.


RE: please use Celsius
By Seemonkeyscanfly on 5/21/2008 11:27:28 AM , Rating: 2
It more fun to have the freezing point at 32 degrees. That way it does not sound as cold as 0 degrees.

We tried to convert in the late 70's early 80's. For about 3 or 4 years students had to learn both US standard and metric. Then our Government just stopped. For some reason they decided it was not worth the change. I was to young to care to ask why we stopped.


RE: please use Celsius
By GaryJohnson on 5/21/2008 12:32:07 PM , Rating: 3
I think Belize still uses Farenheit.


RE: please use Celsius
By Ringold on 5/21/2008 12:42:43 PM , Rating: 2
Simple solution.

Kris can look at site traffic. If it's predominately from the US, he's serving his market best by having the news posters use Fahrenheit.

If it's mostly European, then Celsius with a touch of collectivism may be in order.

If we're all going by what most people are doing, then why Spanish? That's a huge form of arrogance in itself. Only 322 million people speak Spanish. 873 million people speak Mandarin. Natively, anyway. More people, I believe, can speak English than any other language.


RE: please use Celsius
By the goat on 5/21/2008 10:29:39 AM , Rating: 2
quote:
Please dont post temperature in Fahrenheit. The rest of the world uses Celsius.


That is like saying "Please don't make any products for left handed people because most people are right handed."

That article included both Fahrenheit and Kelvin measurements. Honestly what are you complaining about?


RE: please use Celsius
By djkrypplephite on 5/21/2008 12:54:00 PM , Rating: 1
If you could also include a box of tissues in each article . . .


RE: please use Celsius
By Polynikes on 5/21/2008 1:58:20 PM , Rating: 2
Should we change all the speed limit signs to KM/H when you come over here to visit? We'd like to know ahead of time so we don't have another fiasco like this.


RE: please use Celsius
By EODetroit on 5/22/2008 10:24:58 AM , Rating: 1
Well who gives a damn? But if you must...

If the article is aimed at the average American reader, then Fahrenheit is fine for common temperatures, Celcius is also fine for extreme temperatures that people don't experience in everyday life, no matter what the topic.

If its a scientific article that presumably non-technical people won't be interested in, then Celcius should be used, because that's what's used in science, even in the United States.

And if its aimed at Americans and its weather related, Fahrenheit should be used no matter what, because that's how we report the weather in the States.

But this is a trifle to complain about, I agree with all the people saying "QQ moar" and the like.


RE: please use Celsius
By eea on 5/22/2008 12:32:29 PM , Rating: 2
It seems like the posters here have never had a job in industry! Rankine is used and is a absolute scale like kelvin. If your calculations use pounds for mass flow, Rankine follows.


RE: please use Celsius
By Trippytiger on 5/24/2008 1:34:50 AM , Rating: 2
quote:
It seems like the posters here have never had a job in industry in the United States ! Rankine is used and is a absolute scale like kelvin. If your calculations use pounds for mass flow, Rankine follows.


Fixed that for you.


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