1. By :
Tanvi Jain
Aditi Gupta

2. HEIKE . K . ONNES
He was the first Scientist
who studied about
SUPERCONDUCTIVITY.
Mercury (Tc = 4.2 K)
Helium (B.P = 4.2K)

3. Extremely Surprising Result :
RRESISTANCEESISTANCE ==== 00

4. The following table shows the Critical
Temperature of various Superconductors :-
MATERIAL TYPE CRITICAL
TEMPERATURE (K)
ZINC METAL 0.88 k
ALUMINIUM METAL 1.19 k
TIN METAL 3.72 k
CREAMICS PEROVSKITES 37 K
YTTRIUM BARIUM
COPPER OXIDE
ALLOY 92 K
NIOBIUM METAL 9.2 K
MAGNESIUM I
BOURIDE
ALLOY 138 K
MERCURY BARIUM
CALCIUM COPPER
OXIDE
ALLOY I64 K ( Under 30 G Pa
of Pressure )
LEAD METAL 7.2 K

5. YTTRIUM BARIUM COPPER OXIDE

6. Theories Explaining Superconductivity :
During 1950s
Ginzburg & Landau Theory
{ Mathematical }
Barden Cooper Scieffer (BCS) Theory
{ Microscopic }

8. GINZBURG & LANDAU THEORY :
Without Magnetic Field :
Below Superconducting Transition
Temperature :

9. Bardeen Cooper Schrieffer Theory
The electrons pair to the fermi level (10^-15 m)
This is known an PHONON interaction..

11. What actually happens at Low Temperature ?
Region of
vibration
Electron
Lets go
Critical Temp.
Reached…
Now lets
understand
the cooper
interaction…
This part
becomes +vely
charged….
And ….

12. Understanding Cooper Pair Interaction…
The Cooper Interaction (BCS theory)

13. PROPERTIES OF
SUPERCONDUCTIVITY
 No Power Loss :
 Electrons can travel through them
freely.
 They can carry large amounts of
electrical current for long periods
of time without losing energy as
heat.
 Meissner Effect :
 Perfect dimagnetism.
 Has implications for making high
speed, magnetically-levitated
trains.

14. The classic demonstration of the MEISSNER EFFECT.

16. MAGLEV TRAIN

18. MAGLEV
Use copper coils in the track which use repulsion to lift the train up
to make it levitate.
Superconducting magnets on the train.
TRACK MAGNETS – Accelerate and brake

19. MAGNETIC RESONANCE IMAGING
(MRI) :

20. MRI OUTPUT (BRAIN)

21. NUCLEAR MAGNETIC
RESONANCE (NMR) :

22. ABOUT NMR :
Drug discovery, biotechnology & materials science.
Homogeneous & Strong Magnets in NMR spectroscopy.

23. MAGNETOMETER :
LOGIC : SENSING VERY SMALL MAGNETIC FIELDS.
Used to detect Submarines.
Measure the magnetic field produced by your brain.
To find ore deep deposited underground.
Sense minute signals from stars etc.