Demonstration of the Meissner Effect Using Superconducting Y2BaCuO5 (YBCO)

1
Demonstration of the Meissner Effect Using
Superconducting Y2BaCuO5 (YBCO)

• Michael Moore
• College of the Redwoods
• Superconducting Magnet Program
• Lawrence Berkeley National Lab

2
Y2BaCuO5 is a High Temperature Superconductor
The critical temperature(Tc) is the temperature
at which a material becomes superconductive
LN-80 K
LHe-4.2 K
3
YBCO is a Type II Superconductor

• Type I has a much sharper transition to
  superconductivity and exhibits perfect
  diamagnetism
• Type II allows flux pinning and has a higher Tc
• The Meissner Effect only occurs in Type II

Non-superconductive metals
Resistance
Type II
Type I
0 O
Tc
0 K
4
Superconductivity Creates Diamagnetism
The surface of the YBCO assumes the same Flux
value as the external flux from the magnets and
allows none of it to enter the YBCOs interior.
Because Like poles repel each other, the YBCO is
levitated
5
Impurities in the YBCO Causes Flux Pinning
Impurities(non-superconducting materials) pin
flux lines in flux lattice votices

• Diamagnetism in superconducting material

6
The Meissner Effect is a Combination of
Diamagnetism and Flux Pinning
Permanent Magnet
Type II superconductor

• The classic Meissner Effect demonstration

7
Flux Density and Magnetic Flux Lines of Track
Configuration
Low Density
Flux Lines
High Density
Permanent Magnets
8
The YBCO will only move along the track

• Flux Pinning will only allow flux lines of the
  same value to enter the vortexes
• Since the values only stay the same in a line
  parallel to the track, the YBCO only moves in
  that direction

YBCO
9
Liquid Nitrogen Cools the YBCO Below its Tc
Liquid Nitrogen
YBCO
When the LN boils away, the YBCO stays
superconducting for 3 minutes
10
Acknowledgements

• I would like to thank my mentor, Stephen Gourlay
  for his guidance and support on this project,
  Zach Radding for Design works involvement,
  Kathleen Weber for helping me get used to lab
  culture, Ron Scanlen, Dan Dietderich, GianLuca
  Sabbi and Shlomo Caspi for their help with the
  properties of superconductors, Jim Swithwick for
  computer assistance, Alan Lietzke for putting up
  with my love for gauss meters, Jim Swanson, Hugh
  Higley, Scott Bartlett, Ray Hafalia, Roy
  Hannaford, and Nate Liggens who all helped
  immensly with tools and inspiration. A big thanks
  to Goli Modeste who took the time to machine
  parts for me. Jon Zbasnik was a great
  inspiration, and Dawn Faessler and Tom Martin
  were great friends that made work more enjoyable.
  Thanks to Sara Mattafirri for sharing her space
  with me. I would also like to thank Laurel
  Egenberger, Susan Aberg and everyone at CSEE who
  made this summer a fulfilling one. Last but not
  least, thanks to the U.S. Department of Energy,
  Office of Science. The research described here
  was performed at the Lawrence Berkeley National
  Laboratory and funded by the Department of Energy
  Office of Science under Contract No.
  DE-AC03-76SF00098.