1. INTRODUCTION Conductor- any material or object that allows
the flow of electricity. A basic necessity in most electrical or
electronics circuit. However even the very best of conductors
resist electricity and thus sometimes inhibit us to a limited range
of application. The demand? Zero resistance. Bringing about one of
the most significant scientific changes in science and technology:
Superconductors.
2. PRINCIPLE OF SUPERCONDUCTVITY Substances are cooled below a
critical temperature. Absence of electrical resistance. Expulsion
of magnetic field. Quantum mechanical phenomenon. Electron will
flow unimpeded by resistance continuing to flow forever
3. A BRIEF HISTORY In 1911 discovery of superconductivity in
mercury by Heike Kamerlingh Onnes. (At approximate temp 4 K) In
1933 Meissner effect in superconductor. In 1986 George Bednorz and
Alex Muller discovered ceramic oxides that super conduct at higher
temperatures. BCS Theory: The key to superconductivity.
4. SUPERCONDUCTORS Materials that exhibit superconductivity
below a critical temperature Tc. Existence of a critical magnetic
Field (Hc). Hc=H0[1-(T/Tc)] Electron pairs (bosons).
5. MATERIALS
6. Chemical elements.(mercury,lead) Alloys(niobium-titanium)
Ceramics(YBCO) Organic superconductors. (Carbon nanotubes,
Fullerene)
7. PROPERTIES Zero electrical resistance. Meissner effect
Isotope effect (T=const/Ma) Josephson junction Tc directly
proportional to applied pressure.
8. SUPERCONDUCTOR TYPE I Exists in two states. Only one
critical magnetic field (Bc) No presence of any intermediate
states. Soft super conductors. Presence of complete Meissner
effect. Examples: Pb,Hg,Zn etc. Meissner
9. Exists in two states along with a third intermediate state.
Two critical magnetic fields present (Bc1 ,Bc2). Hard super
conductors. Partial presence of meissner effect. Examples: Nb3Sn,
Nb3Ge,Nb3Al. SUPERCONDUCTOR TYPE II
10. BCS THEORY Bardeen-Cooper-Schrieffer theory formulated in
1957 Bound state of electrons in superconductor. Cooper pairs.
12. DISADVANTAGE Very high electric current destroys
superconductivity. Need for cryogenic support. Non economical.
Sensitive to moving magnetic Fields.
13. ULTRACONDUCTORS A new revolution.
14. Room temperature superconductors. Processed from polar
dielectric polymers. Absence of heat generation. Light weight and
economical. Scope of faster computers. Ultraconducting wires
revolutionising the electrical grid. Patented product, being
developed keeping commercialization in mind. ULTRACONDUCTORS
15. ULTRACONDUCTING POLYMERS Thin films of approx (1-100
microns). Fabricated from polymers such as: Olefin Acrylate Silicon
based blastics. Very high electrical conductivity (> 1011 S/cm
-1) Highly efficient and lightweight.
16. Superconductors are a topic of extensive worldwide
research. They are the underlying science behind many new
technologies like the carbon nanotubes.The sheer brilliance of this
object is yet to be applied to full use. If ultra conductors are
fully commercialized it would enhance the contribution of its
predecessor. Energy is endangered and any technology that strives
for a better handlement of electrical power and energy strives for
the betterment of mankind as a whole. CONCLUSION
17. REFERENCE Concepts of modern Physics- Arthur Beisher.
Introduction to superconductivity-Michael Tinkham.
www.superconductors.org www.chavaenergy.com