super conductors and cooper pair
TRANSCRIPT
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SUPER CONDUCTORS
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History of Superconductivity
Superconductivity was discovered by H.
Kamerlingh Onnes in Leiden in 1911 whilestudying the temperature dependence of theelectrical resistance of mercury within a fewdegrees of absolute zero. He observed that theresistance dropped sharply to an immeasurably
small value at a temperature of 4.2K (452F).
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FUNDAMENTALS OF
SUPERCONDUCTORSSuperconductors have the ability to conduct
electricity without the loss of energy. When currentflows in an ordinary conductor, for example copper
wire, some energy is lost. In a light bulb or electric
heater, the electrical resistance creates light and
heat.
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As the electrons begin moving
through the maze , they collide
with tiny impurities or
imperfections in the lattice.
When the electrons bump into
these obstacles they fly off in all
directions and lose energy in theform of heat.
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FLOW IN
SUPERCONDUCTORS
Inside a superconductor the behavior of
electrons is vastly different. The impurities
and lattice are still there, but the movementof the superconducting electrons through
the obstacle course is quite different. As the
superconducting electrons travel through the
conductor they pass unobstructed through
the complex lattice.
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SuperconductivityThe phenomenon of losing resistivity
when sufficiently cooled to a very lowtemperature (below a certain criticaltemperature).
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Critical Temperature (TC)
Temperature at which a normal
conductor loses its resistivity andbecomes a superconductor.
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SUPER CONDUTIVE MATERIALS
Superconductivity occurs in a wide variety of
materials, including simple elements like tin
and aluminium, various metallic alloysand
some heavily-dopedsemiconductors.
Superconductivity does not occur in noble
metalslike goldand silver, nor in pure samples
of ferromagnetic metals.
http://en.wikipedia.org/wiki/Tinhttp://en.wikipedia.org/wiki/Aluminiumhttp://en.wikipedia.org/wiki/Alloyhttp://en.wikipedia.org/wiki/Doping_(semiconductor)http://en.wikipedia.org/wiki/Semiconductorhttp://en.wikipedia.org/wiki/Noble_metalhttp://en.wikipedia.org/wiki/Noble_metalhttp://en.wikipedia.org/wiki/Goldhttp://en.wikipedia.org/wiki/Silverhttp://en.wikipedia.org/wiki/Ferromagnetismhttp://en.wikipedia.org/wiki/Ferromagnetismhttp://en.wikipedia.org/wiki/Silverhttp://en.wikipedia.org/wiki/Goldhttp://en.wikipedia.org/wiki/Noble_metalhttp://en.wikipedia.org/wiki/Noble_metalhttp://en.wikipedia.org/wiki/Semiconductorhttp://en.wikipedia.org/wiki/Doping_(semiconductor)http://en.wikipedia.org/wiki/Alloyhttp://en.wikipedia.org/wiki/Aluminiumhttp://en.wikipedia.org/wiki/Tin -
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Explanation
In conductors current flows by themovement of individual electrons.
In superconductive materials currents flowsby the movement of pair or electron.
This electron pair is named as COOPERPAIR
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Cooper Pair
A Cooper pair is two electrons that arebound together at low temperatures in acertain manner.
First described in 1956 by Americanphysicist Leon Cooper.
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When electrons are passing through thesuperconductive material its atoms
experiences the deformation. This deformation helps the electrons to
foam pair and move through the lattice.
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How the Cooper pairs are formed
One theory is an electron passing by thecrystal lattice of atoms in the conductor
distorts the lattice in such a way the nextelectron is attracted to the lattice distortion.
Or instead of the electron-pairing being
mediated by lattice vibrations, the interactionof the conduction electrons may be due tocharge or electron spin fluctuations in someelectronic subsystem.
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How do two electrons stick together tomake a pair? As they repel each other, dont
they? Two isolated electrons do repel each other, but
two electrons in a superconductor arentisolated
theyrein the middle of a huge lattice of positivelycharged atoms making up the solid.
Two electrons by themselves cant be stuck
together, but two electrons inside a lattice candevelop an attractive force between them thatsmediated by the lattice.
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Applications of Superconductors
MEDICAL:# Biotechnical engineering# Nuclear Magnetic Resonance (NMR)# Diagnosis of brain tumor
INDUSTRIAL:# Separation
# Magnets# Sensors & Transducers# Magnetic Shielding
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ELECTRONICS:# SQUIDs# Transistors
# Josephson Junction Devices# Circuitry Connections# Particle Accelerators
# Sensors# Memory Storage Element inComputers
Transportation:# Magnetically Levitated Vehicles# Marine Propulsion
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Power Generation:
# Motors
# Generators# Energy Storage
# Transmission
# Fusion# Transformers and Inductors