1. START

2. What’s “SUPER” about SUPERCONDUCTORS? Clarina R. dela Cruz High Pressure and Low Temperature Laboratory Texas Center for Superconductivity University of Houston

3. metals wood Conductors vs. Insulators plastics All electrons are PAIRED FREE ELECTRONS

4. What is Resistance? What is Resistance? ELECTRIC FIELD VOLTAGE DIFFERENCE IONS (+) ELECTRONS (-)

5. conductors superconductors T c  critical temperature R=0 Zero resistance Zero power loss

6. BCS Theory John Bardeen Leon Cooper John Schrieffer (1957) No collisions Zero resistance

7. The Meissner-Ochsenfeld Effect Walter Meissner Robert Ochsenfeld (1933) T>T C T<T C Superconductor Magnet DIAMAGNETISM ?

8. Properties of a Superconductor Zero resistance diamagnetism

9. 295 K,room temp 373 K,BP of water 273 K,FP of water 77 K,Liquid Nitrogen 4.2 K,Liquid Helium

10. Low -T c Superconductivity Heike Kamerlingh Onnes (1911)

11. LOW-t C Superconductors Lead (Pb) Mercury (Hg) Aluminum (Al) Gallium (Ga) Molybdenum (Mo) Zinc (Zn) Zirconium (Zr) Americium (Am) Cadmium (Cd) Ruthenium (Ru) Titanium (Ti) Uranium (U) Hafnium (Hf) Iridium (Ir) Beryllium (Be) Tungsten (W) Platinum (Pt)* Rhodium (Rh) 7.196 K 4.15 K 1.175 K 1.083 K 0.915 K 0.85 K 0.61 K 0.60 K 0.517 K 0.49 K 0.40 K 0.20 K 0.128 K 0.1125 K 0.023 K 0.0154 K 0.0019 K 0.000325 K

12. High-T c Superconductivity Alex Müller and Georg Bednorz Paul Chu 164 K

13. 295 K,room temp 373 K,BP of water 273 K,FP of water 77 K,Liquid Nitrogen 4.2 K,Liquid Helium 138 K,Highest Tc for HgBaCaCuO

14. Applications

15. What lies ahead? Search for more efficient cryogenic cooling ROOM TEMPERATURE SUPERCONDUCTIVITY ?

16. REFERENCES http://superconductors.org http://www.lancs.ac.uk