New superconductors present new mysteries, possibilities

Jun 04, 2008

Johns Hopkins University researchers and colleagues in China have unlocked some of the secrets of newly discovered iron-based high-temperature superconductors, research that could result in the design of better superconductors for use in industry, medicine, transportation and energy generation.

In an article published today in the journal Nature, the team, led by Chia-Ling Chien, the Jacob L. Hain Professor of Physics and director of the Material Research Science and Engineering Center at The Johns Hopkins University, offers insights into why the characteristics of a new family of iron-based superconductors reveal the need for fresh theoretical models which could, they say, pave the way for the development of superconductors that can operate at room temperature.

"It appears to us that the new iron-based superconductors disclose a new physics, contain new mysteries and may start us along an uncharted pathway to room temperature superconductivity," said Chien, who teamed up on the research with Tingyong Chen and Zlatko Tesanovic, both of Johns Hopkins, and X.H. Chen and R.H. Liu of the Hefei National Laboratory for Physical Science at Microscale and Department of Physics, University of Science and Technology of China in Anhui, China.

Superconductors are materials that can carry electrical current without friction and as a result, don't waste electrical energy generating heat. (Imagine your laptop computer or PC not getting warm when it is turned on.) This means that an electrical current can flow in a loop of superconducting wire forever without a power source. Today, superconductors are used in hospital MRI machines, as filters in cell phone base stations and in high-speed magnetic levitating trains.

Unfortunately, most of today's superconducting materials can only function and operate at extremely low temperatures, which means that they must be paired with expensive supercooling equipment. This presents researchers with a grand challenge: to find superconducting material that can operate at more "normal" temperatures.

"If superconductors could exist at room temperatures, the world energy crisis would be solved," Chen said.

Chen explains that though all metals contain mobile electrons which conduct electricity, a metal becomes a superconductor only when two electrons with opposite "spins" are paired. The superconductor energy "gap," which is the amount of energy that would be needed to break the bond between two electrons forming such a pair to release them from one another, determines the robustness or strength of the superconducting state. This energy gap is highest at low temperatures, but vanishes at the temperatures at which superconductivity ceases to exist.

"This gap -- its structure and temperature dependence -- reveal the 'soul' of the superconductor, and this is what was measured in our experiment," Chien said.

The team measured this gap and its temperature variation, revealing that the pairing mechanism in iron-based superconductors is different from the one in more traditional, copper-based, high-temperature superconductors. To the researchers' surprise, their results were incompatible with some of the newly proposed theories in this mushrooming field.

"In the face of this discovery, it is clear that we need to reexamine the old and invent some new theoretical models," Tesanovic said. "I predict that these new, iron-based superconductors will keep us physicists busy for a long, long while."

Source: Johns Hopkins University

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User comments : 9

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zevkirsh
2.3 / 5 (7) Jun 04, 2008

"If superconductors could exist at room temperatures, the world energy crisis would be solved," Chen said. --pure nonsense.
Mombo_Dogface
3.8 / 5 (4) Jun 04, 2008
Zevkirsh.
Your going to have to do better than just saying "Pure Nonsense". Please explain your reasoning behind it being "Pure Nonsense". A 5 year old could make the same argument.
Soylent
3.8 / 5 (5) Jun 04, 2008

"If superconductors could exist at room temperatures, the world energy crisis would be solved," Chen said. --pure nonsense.


It would be enormously helpful.

It would make electric engines, generators, transformers and power lines smaller and reduce losses.

Wind and solar would go from being completely useless and a waste of natural gas for grid scale energy generation to potentially useful sources by allowing cheap and efficient storage in arrays of large Superconducting Magnetic Energy Storage devices and allowing much cheaper transmission of electric power over very long distances.

It would allow nuclear power to expand its role from only base-load power to providing both base-load and peak-load, eliminating the need for expensive natural gas.

The problem it (most likely) won't solve is the energy storage problem for electric vehicles. SMES isn't dense enough for them without much higher critical current than current super conductors have achieved and there would be a worry over the health implications of being subjected to very strong magnetic fields for long periods over time.
zevkirsh
2.5 / 5 (4) Jun 04, 2008
pure nonsense.....because the energy problem is not a problem of transmission, it' is primarily one of energy supply and then energy storage and only then...transmission. but of course, pushing the line of efficiency in transmission will ease up the difficulties of supply and storage.
z
earls
3 / 5 (2) Jun 04, 2008
There is no shortage of free, cheap energy - storage is the issue. As Soylent pointed out "SMES" would go a long way to making energy portable and readily accessible thereby eliminating the need to transport power over lines altogether.

I would also think that one super-conductor could induce a current (transfer energy) to another super-conductor wirelessly as well.

Room temperature super-conductors hold an amazing capacity of potential. Literally. :p
hudres
5 / 5 (3) Jun 04, 2008
This article says absolutely nothing. What is the critical temperature of this new material? Without stating this, it is impossible to tell whether this material is any better or worse than existing materials. I am disappointed 73
out7x
1 / 5 (2) Jun 05, 2008
Nothing new about iron having many electron energy levels. Electron spin pairs energy gap is the question.
lengould100
3 / 5 (2) Jun 05, 2008
Initial reaction is to agree with the above [QUOTE] --pure nonsense [/QUOTE] opinion, as the largest contribution superconductors could make to existing electrical infrastructure is to eliminate the I^2R thermal loss inefficiencies which, really, aren't that large. Typically 5% in transmission, perhaps 10% in generation. Many end uses of electricity wouldn't benefit at all (eg. cooking or heating). Many motor application mich also gain perhaps 10% efficiency (still will have bearing and windage losses, which are significant).

Anyway, sounds like any rational use of the discovery is many many years out, with many questions unanswered, eg. does the effect disappear in presence of a magnetic field, making it useless for motor windings, as with current high-temp superconductors?
ontheinternets
1 / 5 (1) Jun 05, 2008
Concerning solar power.. If we had room-temperature superconductors for lossless transmission, we could consider networking the electric grid around the planet, and thus avoid some of the storage problem by allowing people to tap into solar power at night ;)

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