This document provides an overview of superconductivity. It begins with definitions and the discovery of superconductivity by Kamerlingh Onnes in 1911. It describes the Meissner effect and the development of BCS theory in 1957 to explain superconductivity through Cooper pairs. It outlines several properties of superconductors like the Josephson effect and reviews applications such as magnetic levitation and power transmission. It concludes by noting superconductivity enables enormous power transfer without loss below critical temperatures.
Superconductivity is the ability of certain materials to conduct electric current with practically zero resistance. This capacity produces interesting and potentially useful effects. For a material to behave as a superconductor, low temperatures are required.
Basic Information regarding superconductors.
Superconductivity is a phenomenon of exactly zero electrical resistance and expulsion of magnetic fields occurring in certain materials when cooled below a characteristic critical temperature.
This power-point presentation include
1. Introduction to Superconductors
2. Discovery
3. Properties
4. Important factors
5. Types
6. High Tc Superconductors
7. Magnetic Levitation and its application
8. Josephson effect
9. Application of superconductors
#Tip- You can further add videos which are available in vast amount on YouTube regarding superconductivity(specially magnetic levitation)
P.S.Does not contain information about Cooper pairs and BCS theory
Basically i have tried giving every details about the phenomenon Superconductivity in the simplest way. This is my first upload.I'll be very glad if u all give your valuable feedback. Thank u.
Properties of superconductors, Effects of the magnetic field, variation of resistance with temperature, Meissner Effect, isotope effect, Energy Gap, Coherence Length, BCS Theory, Types of superconductors ,
Superconductivity is the ability of certain materials to conduct electric current with practically zero resistance. This capacity produces interesting and potentially useful effects. For a material to behave as a superconductor, low temperatures are required.
Basic Information regarding superconductors.
Superconductivity is a phenomenon of exactly zero electrical resistance and expulsion of magnetic fields occurring in certain materials when cooled below a characteristic critical temperature.
This power-point presentation include
1. Introduction to Superconductors
2. Discovery
3. Properties
4. Important factors
5. Types
6. High Tc Superconductors
7. Magnetic Levitation and its application
8. Josephson effect
9. Application of superconductors
#Tip- You can further add videos which are available in vast amount on YouTube regarding superconductivity(specially magnetic levitation)
P.S.Does not contain information about Cooper pairs and BCS theory
Basically i have tried giving every details about the phenomenon Superconductivity in the simplest way. This is my first upload.I'll be very glad if u all give your valuable feedback. Thank u.
Properties of superconductors, Effects of the magnetic field, variation of resistance with temperature, Meissner Effect, isotope effect, Energy Gap, Coherence Length, BCS Theory, Types of superconductors ,
Super conductors,properties and its application and BCS theorysmithag7
superconductors:-Introduction, definition, type1,type2 and atypical. Preparation of high temperature super conductor-Y1 Ba2Cu3Ox±δ, BCS theory and general application of high temperature super conductors.
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Super conductors,properties and its application and BCS theorysmithag7
superconductors:-Introduction, definition, type1,type2 and atypical. Preparation of high temperature super conductor-Y1 Ba2Cu3Ox±δ, BCS theory and general application of high temperature super conductors.
The uploader doesn't own any rights on the contents of this presentation file. Most of the contents are from www.wikipedia.org
Feel free to share this presentation file under Creative Commons license "Attribution-NonCommercial-ShareAlike"
(CC BY-NC-SA)
Thanks
The fascinating phenomenon of superconductivity and its potential applications have attracted the attention of scientists, engineers and businessmen.
Superconductivity was discovered in 1911 by Heike Kamerlingh Onnes, as he studied the properties of metals at low temperatures.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
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Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
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Monitor common gases, weather parameters, particulates.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
2. Outline:
• Definition of Superconductivity
• Discovery
• The Meissner Effect
• BCS Theory
• Properties of Superconductivity
• Applications of Superconductivity
• Conclusions
3. Definition of Superconductivity
Superconductivity is a phenomenon occurring in
certain materials generally at very low
temperatures , characterized by exactly zero
electrical resistance and the exclusion of the
interior magnetic field .
In simple words For some materials, the
resistivity vanishes at some low temperature: they
become superconducting ,such materials are
called superconductors .
4. Discovery
• Superconductivity was discovered on 1911 by
Heike Kamerlingh Onnes , who was studying
the resistance of solid mercury at cryogenic
temperatures using the recently-discovered
liquid helium as a refrigerant .
• At the temperature of 4.2 K, he observed that
the resistance suddenly disappeared. In
subsequent decades, superconductivity was
found in several other materials.
5. Critical Temperature
The temperature at which electrical resistance is
zero is called the Critical temperature (Tc)
The cooling of the material can be achieved using
liquid nitrogen or liquid helium for even more lower
temperature.
6.
7. The Meissner Effect
The limit of external magnetic field strength at
which a superconductor can exclude the field is
known as the critical field strength, Hc.
In 1920 Meissner discovered not only did
superconductors exhibit zero resistance but also
spontaneous expel all magnetic flux when cooled
through the superconducting transition , that is
they are also perfect dimagnets .
We call this the Meissner effect .
9. BCS THEORY
• The complete microscopic theory of
superconductivity was finally proposed in 1957
by Bardeen , Cooper , and Schrieffer . This BCS
theory explained the superconducting current as
a super fluid of Cooper pairs , pairs of electrons
interacting through the exchange of phonons.
For this work, the authors were awarded the
Nobel Prize in 1972.
10. BCS – COOPER PAIRS
• A Cooper pair is the name given to electrons that
are bound together in a certain manner first
described by Leon Cooper . In normal
superconductors, the attraction is due to the
electron interaction.
• The Cooper Pair state forms the basis of the BCS
theory of superconductivity .
11. Formation of cooper pairs
Cooper pairs are formed by
an attractive force
between electrons from
the exchange of phonon.
The energy of phonon is
usually less than 0.1eV
12. • When a metal is cooled to the critical temperature,
electrons in the metal form Cooper Pairs.
• Cooper Pairs are electrons which exchange
phonons and become bound together.
• Bound electrons behave like bosons. Their
wavefunctions don’t obey Pauli exclusion rule and
thus they can all occupy the same quantum state.
• The BCS theory of Superconductivity states that
bound photons have slightly lower energy, which
prevents lattice collisions and thus eliminates
resistance.
• As long as kT < binding energy, then a current can
flow without dissipation.
14. Josephson effect
• When two superconductors are joined by a thin
,insulating layer ,it is easier for the electron pairs
to pass from one superconductor to another
without resistance .
• This is called the Josephson effect
• This effect has applications for superfast
electrical switches that can be used to make
small ,high speed computers.
15. Specific heat
• A finite jump in the specific heat is observed at
the critical temperature.
• In a superconducting phase, the electron
resistance changes with the jump , while the
energy undergoes a continuous variation .
• When the substance is cooled its specific heat
typically decreases but at the critical temperature,
it increases suddenly.
16. Super fluidity
• This phenomenon was first observed in Helium
at a temp below 2.17 K. helium at this temp flow
quite freely without any friction , through any
gaps and even small capillary tubes.
• Once it is set in motion it will keep on flowing
forever-if there are no external forces acting
upon it.
• Unlike all chemicals helium does not solidify
when cooled down near absolute zero.
17. Thermal conductivity
• In an ideal superconductor , there is a marked
drop in the thermal conductivity when
superconductivity sets in .
• In non ideal superconductors an increase in
thermal conductivity on becoming super
conducting has been observed in few specimens.
18. Isotope effect
• It has been observed that critical temperature
varies with isotopic mass.
• i.e., critical temperature is inversely
proportional to the square root of mass of the
isotope
19. Field intensity
• Removal of the superconductivity state does not
only occur by raising the temperature , but also
by subjecting a material to a magnetic field .
• The critical value of magnetic field for the
destruction of superconductivity , Hc is function
of temperature , at T=Tc , Hc =0 .
• With only small deviations, the critical field Hc
varies with the temperature according to the
parabolic law,
Hc =H0 [ 1 – (T/Tc )2 ]
20. • The magnetic field which causes a superconductor to
become normal from superconducting state is not
necessarily an external applied field , it may rise as a
result of electric current flow in the conductor.
• In a long superconductor wire of radius r, the super-
conductivity may be destroyed when a current I
exceeds a critical current value Ic, which at the
surface of wire produce a critical field H is given by Ic
= 2 *3.14*rHc
called Silsbee’s rule
22. Applications of Superconductivity
Some of them are:
- Magnetic levitation(Maglev)
- Magnetic Field Detection
- (SQUID)
- Power Transmission
- Superconducting Generators
23. Conlusions
• That superconductivity is one of the important
discoveries in the field of modern physics.
• The mentioned properties predicts that the
superconductivity can be classified into different
types.
• The advantage of superconductors is their
capability of carrying enormous amount of power
without loss under critical temperature, so
superconductors can save a lot of energy.
24. References
• Concepts of modern Physics- Arthur
Beiser.
• Introduction to superconductivity-Michael
Tinkham.
• www.superconductors.org
• www.chavaenergy.com