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Science: Can diamond now be a superconductor?
Physicsweb ^ | 4 April 2003 | Peter Rodgers is Editor of Physics World

Posted on 04/16/2003 5:00:15 PM PDT by Ernest_at_the_Beach

A physicist in South Africa claims to have created a new superconducting state of matter at room temperature. Johan Prins of the University of Pretoria observed the superconducting state in experiments with diamonds that had been doped with oxygen (Semiconductor Science and Technology 18 S131).

Diamond is a semiconductor and Prins has long been interested in using n-type diamond as a "cold" cathode to replace the "hot" cathodes found in television tubes and many other devices. Moreover, he believes that the results of his experiments on n-type diamond surfaces - made by exposing the diamond to energetic oxygen ions - can only be explained by a new type of superconducting state. "If it is not superconductivity then it must be violating the second law of thermodynamics," he says.

Click to enlarge

In his experiments, Prins measures the current that flows between the diamond and a gold-plated probe as the distance between them is varied. When a voltage of +1000 V is applied, the current always settles down at a value of about 0.5 mA for separations up to about 16 µm, after which it falls to zero. A current also flows in the opposite direction when a voltage of -1000 V is applied, but it decreases more rapidly with distance. The experiments are performed at room temperature in a vacuum of 10-6 mbar.

Prins argues that a thin "electron-charge" layer is formed in the vacuum just above the surface of the diamond, and that a depletion layer of positive charges forms in the diamond. This is similar, he says, to the Schottky diode that is generated between an n-type semiconductor and a metal. Prins then applies the equations that describe electron transport through a Schottky diode to his system. He finds that as more and more electrons are extracted from the diamond, the density of electrons in this layer reaches a critical value at which a Bose-Einstein-type condensate of electron pairs forms. Current continues to flow from the diamond cathode through this layer to the anode, even though there is no voltage across the layer - a sign of superconductivity.

However, the rest of the diamond community remains to be convinced. Richard Jackman of University College London, who edited the special issue of the journal in which Prins' papers appear, describes them as "largely theoretical papers, thought provoking and very controversial - the end conclusions remain open to debate".

Prins admits that he must show that the state can expel magnetic fields to conclusively prove that the state is superconducting. However, he has recently retired and does not have the facilities to perform such an experiment. He has offered to fly his samples to another lab but has not yet found any volunteers. Prins and two colleagues are also trying to secure patents on the ideas.

In addition, Prins is half-way through writing six theoretical papers that will, he claims, fully explain the results and shed new light on the mechanisms underlying high-temperature superconductivity.

Author
Peter Rodgers is Editor of Physics World


TOPICS: Business/Economy; Extended News; Technical
KEYWORDS: basicscience; diamond; physics; superconductor; techindex
A new superconducting state of matter at room temperature

Is this an attempt to revive the diamond industry?

1 posted on 04/16/2003 5:00:15 PM PDT by Ernest_at_the_Beach
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To: *tech_index; Sparta; freedom9; martin_fierro; PatriotGames; Mathlete; fjsva; grundle; beckett; ...
Anyone heard of this?

Superconducting at room temperature would be a big deal!

OFFICIAL BUMP(TOPIC)LIST

2 posted on 04/16/2003 5:02:16 PM PDT by Ernest_at_the_Beach (Where is Saddam? and where is Tom Daschle?)
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To: Ernest_at_the_Beach
let me know when they start buying kidney stones for superconductors
3 posted on 04/16/2003 5:06:09 PM PDT by joesnuffy (Moderate Islam Is For Dilettantes)
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To: Ernest_at_the_Beach
For it to be workable, it would need to be a synthetic diamond layer on some substrate. You need to have the actual superconductor be long enough to actually be useful.
4 posted on 04/16/2003 5:07:07 PM PDT by SauronOfMordor (Heavily armed, easily bored, and off my medication)
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To: Ernest_at_the_Beach
what a waste of good jewelery ; )
5 posted on 04/16/2003 5:08:11 PM PDT by xsmommy
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To: xsmommy
Why, it is just a rock!
6 posted on 04/16/2003 5:09:20 PM PDT by Ernest_at_the_Beach (Where is Saddam? and where is Tom Daschle?)
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To: Ernest_at_the_Beach
"Superconducting at room temperature would be a big deal! "

It would be a very big deal.
My son did some post-grad work in this area at the University of Houston with Paul Chu.

7 posted on 04/16/2003 5:10:11 PM PDT by blam
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To: Ernest_at_the_Beach
Superconducting at room temperature would be a big deal!

AlGore would have a job till the end of time.

8 posted on 04/16/2003 5:11:17 PM PDT by husky ed (FOX NEWS ALERT "Generalissimo Francisco Franco is still dead" THIS HAS BEEN A FOX NEWS ALERT)
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To: Ernest_at_the_Beach
a nice sparkly one!
9 posted on 04/16/2003 5:11:34 PM PDT by xsmommy
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To: Ernest_at_the_Beach
So...you have a quasi two-dimensional layer of charge that is so narrow that the ground state energy is separated from the first excited state by more than the lowest phonon excitation mode...so that phonon scattering can't push electrons out of the ground state...

or something like that...

10 posted on 04/16/2003 5:29:48 PM PDT by HassanBenSobar (I now inform you that you are too far from reality!)
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To: Ernest_at_the_Beach
Remember Texas A&M published room temp super conductivity.
Their measurements were off.
When another person can duplicate this, it will make more
sense.
11 posted on 04/16/2003 6:00:55 PM PDT by HuntsvilleTxVeteran ( clinton is a raping traitor!)
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To: Ernest_at_the_Beach
Electron transition efficiency on diamond surfaces has been studied for decades... Even before Hagstrum's seminal work on bombardment-induced Auger transitions... Looks like promising stuff...
12 posted on 04/16/2003 6:04:26 PM PDT by maxwell (Well I'm sure I'd feel much worse if I weren't under such heavy sedation...)
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To: Ernest_at_the_Beach
Science: Can diamond now be a superconductor?

It's been known by men, for thousands of years, that a diamond is a superconductor to the bedroom.

The larger, the more conductive.

13 posted on 04/16/2003 6:04:27 PM PDT by Psycho_Bunny
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To: Ernest_at_the_Beach
Half a milliamp at 1000V through a diamond sounds more like a very expensive 2 megaohm resistor than a superconductor.
14 posted on 04/16/2003 6:11:50 PM PDT by Jack of all Trades
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To: Ernest_at_the_Beach
Is this an attempt to revive the diamond industry?

Now you have a friend in the diamond business.

Can you imagine how much more annoying this guy's commercials could get?

15 posted on 04/16/2003 6:16:07 PM PDT by Some hope remaining.
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To: xsmommy
If they get Cubic Zirconium to superconduct, I'm GOLDEN. <|:)~
16 posted on 04/16/2003 6:18:57 PM PDT by martin_fierro (Mr. Avuncular)
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To: Some hope remaining.
My brother-in-law does a KILLER Tom Shane imitation. <|:)~

I don't find his ads so bad.
17 posted on 04/16/2003 6:19:59 PM PDT by martin_fierro (Mr. Avuncular)
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To: Ernest_at_the_Beach
I assume these diamonds would have to be manufactured in order to infuse them with the necessary oxygen ion content?
18 posted on 04/16/2003 6:31:00 PM PDT by semaj
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To: Psycho_Bunny; xsmommy
ROFLMAO***!!!!
19 posted on 04/16/2003 6:32:48 PM PDT by Ernest_at_the_Beach (Where is Saddam? and where is Tom Daschle?)
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To: semaj
I have no idea, I am nowhere close to being an expert on this superconductivity stuff but I did stay at Holiday Express one night!
20 posted on 04/16/2003 6:34:51 PM PDT by Ernest_at_the_Beach (Where is Saddam? and where is Tom Daschle?)
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To: blam
"It would be a very big deal.
My son did some post-grad work in this area at the University of Houston with Paul Chu. "

Paul Chu's (team's) discovery of the high temperature superconductor was a great triumph - for the process as well as the substance of the discovery.

The room-temperature superconductor has been the holy grail since '87. Even if it is as expensive as a diamond, it will be put to use in a million ways.

PS.
The Yttrium-barium-copper superconductors have replaced tons of copper cable in a test application for power delivery, for 400 feet in length under the streets of Detroit. Superconducting cables have five times the power density of copper.


21 posted on 04/16/2003 7:00:06 PM PDT by edwin hubble
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To: Ernest_at_the_Beach
"Why, it is just a rock! "

Yes, and one that burns. A neat and expensive experiment.
(It is carbon, after all).
22 posted on 04/16/2003 7:07:58 PM PDT by edwin hubble
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To: Ernest_at_the_Beach; Jack of all Trades
" the density of electrons in this layer reaches a critical value at which a Bose-Einstein-type condensate of electron pairs forms.

Why should electrons with spin of +-1/2 pair up to essentially form a particle with spin zero and a charge of -2? Where's the driving force? They're both negatively charged, the repulsive force is significant and pairing these fermi particles in this gas involves a higher energy state.

Current continues to flow from the diamond cathode through this layer to the anode, even though there is no voltage across the layer - a sign of superconductivity.

The diamond is acting like a leaky dielectric here. The only reason there is emission from the surface of the diamond is, because the potential of the gold electrode, the anode, is different from that at the surface of the diamond. The field between that surface will be low, because most of it is across the diamond, but it's still there. All that's being observed here is that the mean free path of the electrons in any other direction than the field is much larger than the gap. ie. The electrons don't bump into each other, or into anything else, on the way to the gold plate. Low density electrons, flying though a vacuum, is not a superconducting system.

Also the gap can't be at the same potential as the gold. The gold is positive and the gap is less positive, by there respective makeups and geometry.

It's an expensive 2Mohm resistor.

23 posted on 04/16/2003 7:53:35 PM PDT by spunkets
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To: BraveMan
FYI
24 posted on 04/16/2003 8:35:37 PM PDT by LostThread (no way am I givin' up my rocks for science...lol)
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To: HuntsvilleTxVeteran
They are building on the work of Dr. Emmett Brown, inventor of the Flux Capacitor rated at 1.21Gigawatts.
25 posted on 04/16/2003 8:46:05 PM PDT by ffusco ("Essiri sempri la santu fora la chiesa.")
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To: edwin hubble
Di-Lithium Crystal?
26 posted on 04/16/2003 8:47:13 PM PDT by ffusco ("Essiri sempri la santu fora la chiesa.")
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To: spunkets
Why should electrons with spin of +-1/2 pair up to essentially form a particle with spin zero and a charge of -2? Where's the driving force? They're both negatively charged, the repulsive force is significant and pairing these fermi particles in this gas involves a higher energy state.

I think Bardeen, Cooper and Schrieffer answered this question back in, oh, 1957. Long range interactions, y'know...not only that, once you're dealing with bosons, not fermions, you don't have to follow the same statistics for the distribution in energy states--that is, with fermions, you're limited to 2 per state, but you can have as many bosons as you want in a given state.

27 posted on 04/16/2003 9:58:22 PM PDT by HassanBenSobar (I now inform you that you are too far from reality!)
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To: HassanBenSobar
Yes, Cooper pairs. Those rely on the presence of lattice nuclei though. It involves phonon exchanges that are only possible, because of electrostatic effects of those nuclei and the temperature related regularity and preponderance of lattice's characteristic vibrational modes. In this case there's just a field over a range long enough to always have a measurable potential difference, unless the field between the diamond and the gold has a standing wave pattern from some regular vibrations, or movements of electrodes, or charges.
28 posted on 04/16/2003 11:16:30 PM PDT by spunkets
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To: Ernest_at_the_Beach
Gold is just a weak metal. But it sure is purtee.
29 posted on 04/17/2003 1:04:36 AM PDT by rmlew ("Millions for defense, but not one cent for tribute.")
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To: Ernest_at_the_Beach; Psycho_Bunny; big bad easter bunny
psycho bunny knows the real deal about diamonds and supeconducting!!! ; )

now bunny, i will ask you the same thing that i asked your relative, big bad easter bunny, shouldn't you be coloring eggs somewhere instead of Freeping? ; )

30 posted on 04/17/2003 3:06:18 AM PDT by xsmommy
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To: LostThread
hey Lost Thread, knew i would find you here! we are big fans of diamonds, huh??
31 posted on 04/17/2003 3:07:42 AM PDT by xsmommy
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To: xsmommy
I am the top bunny, I have employees!
32 posted on 04/17/2003 9:22:11 AM PDT by big bad easter bunny
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To: big bad easter bunny
can you at least tell me what i am getting in my easter basket this year? a nice shiny semi-conducting diamond would be nice : )
33 posted on 04/17/2003 9:23:27 AM PDT by xsmommy
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To: Ernest_at_the_Beach
BTFL
34 posted on 04/17/2003 9:54:00 AM PDT by techcor
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To: xsmommy
the bigger the semi-condutor the better, eh?....lol

(I figured, you'd be on this thread too!!)
35 posted on 04/17/2003 1:27:03 PM PDT by LostThread (no way am I givin' up my rocks for science...lol)
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To: Ernest_at_the_Beach
Ah yes...

The advent of the Dilithium crystal.

Damn it Jim
36 posted on 04/17/2003 1:31:22 PM PDT by pray boy
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