super conductors and cooper pair

8/13/2019 Super Conductors and cooper pair

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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

super conductors and cooper pair

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