C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology
description
Transcript of C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology
![Page 1: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/1.jpg)
The Brief History of High Temperature SuperconductivityThe Brief History of High Temperature Superconductivity
The 20The 20thth Anniversary of the discovery of RBCO Anniversary of the discovery of RBCODenver, CO, March 5, 2007Denver, CO, March 5, 2007
“The Brief History of RBCO“The Brief History of RBCO””
C. W. Chu
TCSUH, University of Houston Hong Kong University of Science and Technology
Lawrence Berkeley National Laboratory
TCSUH LBNLHKUST
070221CWC
![Page 2: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/2.jpg)
New York Hilton Hotel, evening of March 18, 1987Woodstock of Physics
070221CWC
![Page 3: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/3.jpg)
![Page 4: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/4.jpg)
Before Bednorz and MuellerBefore Bednorz and Mueller
Experimentally: - Tc ≤ 23.2 K (1974 - 1986) - search for novel materials
Theoretically: - Tc < 30’s K (instabilities) - propose novel mechanisms
Confidence crisis in achieving higher Tc
![Page 5: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/5.jpg)
1986: the critical year1986: the critical year
La2-xBaxCuO4 (214) – new Tc record to 35 K in a new oxides
070221CWC
![Page 6: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/6.jpg)
• The paper was initially greeted with skepticism by most except a few groups
(Tokyo, Houston, Beijing, IBM-Yorktown)
• We confirmed their results in late November
• The 1986 Fall MRS Meeting (Dec. 4):- invited M. K. Wu to join our search
- showed our preliminary resistive data- learned Tokyo’s magnetic and structure data
070221CWC
![Page 7: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/7.jpg)
My group was lucky in the right time with the My group was lucky in the right time with the right experience to tackle the High Tright experience to tackle the High Tc c
problemproblem
searched for FE TiO2-x and SrTiO3-x (1968-71)– learned something about perovskites, FE, and handling oxides
studied BaPb1-xBixO3 (1975-81) – recognized the importance of oxygen in electronic properties and oxide single crystal growth
controlled the structural instabilities by pressure (1974-78) – gained faith in high Tc ,since structural instabilities do not suppress Tc much
examined novel mechanisms proposed – recognized the importance of low dimensionaliy
![Page 8: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/8.jpg)
The unusually large pressure effect on TThe unusually large pressure effect on Tcc
Enhanced TEnhanced Tcc to 40.2 and then to 52.4 K to 40.2 and then to 52.4 K
=> The compound is unusual!!!=> The compound is unusual!!! A TA Tcc>> 40 K defies the then theoretical prediction!!!40 K defies the then theoretical prediction!!!
Science235,567(1987)
070221CWC
![Page 9: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/9.jpg)
060731CWC
….at the University of Houston and at AT&T Bell Laboratories….
Front Page
![Page 10: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/10.jpg)
Submitted in Novemberbefore the deadline 12/5/86
for the APS Meeting in New York in March 1987
Reproduced B&M results:Notes to Alex Mueller & CW Chu expressing my confidence on Tc = 77 K
060731CWC
Dear Wei-kan & Agnus,Wish everything happens to you in this coming year as you wish! Ching-Wu & May P.S. Just got the highest Tc of 40.2 K. Next week very likely 50 K. Now, I am full of confidence of 77 K.
![Page 11: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/11.jpg)
First sign of SC above 77 K was detected on November 25, 1986First sign of SC above 77 K was detected on November 25, 1986in in multimulti-phased but not pure 214 samples!-phased but not pure 214 samples!
Decided the real high TDecided the real high Tcc phase cannot be 214 & phase cannot be 214 &
to stabilize the phase by replacing La with Y & Lu !to stabilize the phase by replacing La with Y & Lu !
Focusing on really high Tc, instead of on the 214-phase,after realizing the signal does not appear in pure 214 samples & destroying 2/3 of our 214-single crystal growth capability!
070221CWC
![Page 12: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/12.jpg)
1987: The Exciting Year
Under the Urge of the University, I prepared a patent application in late December and filed it on January 12,
1987. “..L is an element selected from the group consisting of La, Lu and Y..”
- the basis of later discovery of LBCO & YBCO!
070221CWC
![Page 13: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/13.jpg)
First 90 K - SC was unambiguously observed, although not yet stable.First 90 K - SC was unambiguously observed, although not yet stable.Later analysis of the X-ray data showed it was Later analysis of the X-ray data showed it was
LaBaLaBa22CuCu33OO7 7 (123 or LBCO)(123 or LBCO)
Chu et al.
1987: the exciting year
070221CWC
![Page 14: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/14.jpg)
January
1987: the exciting year
The first 90 K superconductor was 123 LBCO(although not yet pure and thus unstable)
070221CWC
![Page 15: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/15.jpg)
SC above 77 K was finally stabilized.SC above 77 K was finally stabilized.YBaYBa22CuCu33OO77 (123 or YBCO) (123 or YBCO)
the first stable liquid-nitrogen-temperature superconductor.the first stable liquid-nitrogen-temperature superconductor.
(Jan 28-29, 1987)
1987: The Exciting Year
M. K. Wu et al./C. W. Chu et al.
070221CWC
![Page 16: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/16.jpg)
YBaYBa22CuCu33OO77 (YBCO or 123) (YBCO or 123)
March 2, 1987 was a super-day for physics – March 2, 1987 was a super-day for physics – >90K SC, supernova, SSC!!!>90K SC, supernova, SSC!!!
1987: The Exciting Year
070221CWC
1979
![Page 17: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/17.jpg)
1987: The Exciting Year
• Deterimed the YBCO structure with Hazan et al.• Found R electronically decoupled from the sc system
• Synthesized and discovered all RBCOs in about 48 hours in a reduced atmosphere
070221CWC
![Page 18: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/18.jpg)
YBCO: quality epi-films
robusthigh Jc & high Hir above 77 K
The best material for HTS technology
![Page 19: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/19.jpg)
YBCO was included in the White House Millennium Time Capsule Closing Ceremony - December 6, 2000 in the National Archives, Washington DC 070221CWC
![Page 20: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/20.jpg)
070219CWC
After 20 years, we have learned:
•There is no evidence, experimental or theoretical, telling us that room temperature superconductivity
is an impossibility.
•Be prepared to expect the unexpected.
•More excitements are yet to come.
•In Houston, we continue to look for novel HTS,improve existing HTS, understand HTS and
develop new uses of HTS & related materials
![Page 21: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/21.jpg)
7:30 pm3/18/87
Woodstock of Physics
060327CWC
7:30 pm3/18/87
Woodstock of Physics
7:30 pm3/18/87
Woodstock of Physics
![Page 22: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/22.jpg)
The 1987 Team
TCSUH C. W. ChuC. W. Chu: K. Foster, L. Gao, P. H. HorZ. J. Huang, R. L. Meng and Y. Q. Wang
AlabamaM. K. Wu: J. Ashburn and J. C. Torng
Geophysical LabR. Hazan: D. Mao
LANLC. Y. Huang
070221CWC
![Page 23: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/23.jpg)
Thank you!
![Page 24: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/24.jpg)
The Origin of Woodstock of PhysicsIn NY City March 18, 1987
Your abstract was longer than the 4 1/8” allowed (by 1/2 a line)
060801CWC
![Page 25: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/25.jpg)
New York Hilton Hotel, evening of March 18, 1987Woodstock of Physics
070221CWC
![Page 26: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/26.jpg)
The Panel Discussion, March 18, 1987070221CWC
![Page 27: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/27.jpg)
070221CWC
![Page 28: C. W. Chu TCSUH, University of Houston Hong Kong University of Science and Technology](https://reader036.fdocuments.us/reader036/viewer/2022062500/568157c8550346895dc55009/html5/thumbnails/28.jpg)
La-Ba-Cu-O
1G/ Bi-Sr-Ca-Cu-O Tl-Ba-Ca-Cu-O
Hg-Ba-Ca-Cu-O
Hg-Ba-Ca-Cu-OHg-Ba-Ca-Cu-O##
#Under PressureYellow: CWC
La-Ba-Cu-O#
2G/ Y-Ba-Cu-O
La-Ba-Cu-O#
0
Year
1900 1920 1940 1960 1980 2000
Su
per
con
du
ctin
g T
ran
siti
on T
emp
erat
ure
, TC
20
40
60
80
100
120
140
160
180
(K)
Freon
Liquid Nitrogen
Liquid Helium
Nb3Ge
NbCV3Si
Nb-Al-Ge
Nb3SnNbN
NbPbHg
Ba-Ca-Cu-O
Ba-Ca-Cu-OBa-Ca-Cu-O##
Mg-BMg-B
?
070221CWC
?