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[[ImageImej:Meissner effect.jpg|thumb|300px|right|A [[magnetMagnet]] terapung-apung di atas [[superkonduktor "bersuhusuhu tinggi" ]] (dengan [[cecair nitrogen]] didih di bawahnya) menggambarkan [[kesan Meissner]].]]
'''SuperkonduktorKesuperkonduksian''' adalahialah satu fenomena yang wujudterjadi dipada dalamsebilangan [[bahan |bahan-bahan]]yang tertentukhusus yangketika beradasuhunya terlalu rendah (pada peringkat -200 darjah [[suhuCelsius]]), yang rendah,dan dicirikan dengan keadaanoleh [[rintangan elektrik]] yang tepat sifar dan serta mengenepikanmengetepikan [[kesanmedan magnet]] dalaman ([[kesan Meissner]]).
{{BM}}
{{terjemah}}
== Penjelasan ==
In [[conventional superconductor]]s, superconductivity is caused by a [[force]] of attraction between certain [[electrical conduction|conduction]] [[electron]]s arising from the exchange of [[phonon]]s, which causes the conduction electrons to exhibit a [[superfluid]] [[phase (matter)|phase]] composed of correlated ''pairs'' of electrons. There also exists a class of materials, known as [[unconventional superconductor]]s, that exhibit superconductivity but whose physical properties contradict the theory of conventional superconductors. In particular, the so-called [[high-temperature superconductor]]s superconduct at temperatures much higher—though still far below [[room temperature]]—than should be possible according to the conventional theory. There is currently no complete theory of [[high-temperature superconductivity]].
Dalam [[superkonduktor lazim]], kesuperkonduksian dihasilkan oleh [[daya]] tarikan antara elektron-elektron [[Konduksi elektrik|konduksi]]. Daya tarikan ini diwujudkan oleh pertukaran [[fonon]], dan menyebabkan elektron-elektron konduksi menonjolkan [[fasa (jirim)|fasa]] [[bendalir super]] yang terdiri daripada ''pasangan-pasang'' elektron berkorelasi.
Terdapat juga sebuah kelas bahan yang dikenali sebagai [[superkonduktor tak lazim]] yang menonjolkan kesuperkonduksian tetapi sifat-sifat fizikalnya bertentangan dengan teori superkonduktor lazim. Khususnya, [[superkonduktor suhu tinggi]] mensuperkonduksikan pada suhu yang jauh lebih tinggi — walaupun masih jaul lebih rendah daripada [[suhu bilik]] — daripada yang mungkin menurut teori lazim.
Superconductivity occurs in a wide variety of materials, including simple elements like [[tin]] and [[aluminium]], various metallic [[alloy]]s, some heavily-doped [[semiconductor]]s, and certain [[ceramic]] compounds containing planes of [[copper]] and [[oxygen]] [[atom]]s and substrates which are liquid at room temperature such as the unconventional superconductor ([http://www.nims.go.jp/eng/news/nimsnow/Vol1/No4/p2.html NaxCoO2·yH2O]). The latter class of compounds, known as the [[cuprate]]s, are high-temperature superconductors. Superconductivity does not occur in [[coinage metal|noble metals]] like [[gold]] and [[silver]], nor in most [[ferromagnetism|ferromagnetic]] metals, though a number of materials displaying both superconductivity and ferromagnetism have been discovered in recent years.
Masih tidak terdapat sebarang teori yang lengkap terhadap [[kesuperkonduksian suhu tinggi]]. Bagaimanapun, penyelidik-penyelidik di seluruh dunia telah mengkaji topik ini secara mendalam disebabkan ganjaran untuk mengembangkan sebuah teori kesuperkonduksian adalah amat besar. Bukan sahaja penemuannya akan memberikan anugerah [[Hadiah Nobel]], tetapi juga amat menguntungkan. Setiap tahun, berjuta-juta dolar hilang disebabkan kehilangan [[arus elektrik]] ketika mengalir melalui wayar logam yang biasa. Jika kesuperkonduksian dapat terjadi pada suhu yang biasa, jadi setiap wayar di dalam planet ini akan diperbuat daripada bahan yang baru ini dan menyebabkan penjimatan berbilion-bilion dolar.
Superconductivity is an essentially [[quantum mechanics|quantum mechanical]] phenomenon, and cannot be understood simply as the idealization of "[[perfect conductor|perfect conductivity]]" in classical physics.
Kesuperkonduksian terjadi dalam banyak jenis bahan-bahan, termasuk:
==Ciri-ciri asas superkonduktor==
* logam-logam yang biasa seperti [[timah]] dan [[aluminium]]
Most of the physical properties of superconductors vary from material to material, such as the [[heat capacity]] and the critical temperature at which superconductivity is destroyed. On the other hand, there is a class of properties that are independent of the underlying material. For instance, all superconductors have ''exactly'' zero resistivity to low applied currents when there is no magnetic field present. The existence of these "universal" properties implies that superconductivity is a [[phase (matter)|thermodynamic phase]], and thus possess certain distinguishing properties which are largely independent of microscopic details.
* pelbagai [[aloi]] logam
* sesetengah [[semikonduktor]] terdop tinggi
* sesetengah sebatian[[ seramik]] yang mengandungi atom-[[atom]] [[kuprum]] dan [[oksigen]].
The latter class of compounds, known as the [[cuprate]]s, are high-temperature superconductors. Superconductivity does not occur in [[coinage metal|noble metals]] like [[gold]] and [[silver]] when they occur in an elemental form, nor in most [[ferromagnetism|ferromagnetic]] metals, though a number of materials displaying both superconductivity and ferromagnetism have been discovered in recent years; noble metals do exhibit superconductivity when in an alloy. The new high-temperature superconductors are made of a ytterbium alloy in the ratio of a defect perovskite. No one knows why a defect perovskite ratio would exhibit superconductivity.
===Rintangan electrik "at"===
[[Image:CERN-cables-p1030764.jpg |thumb|Kabel elektrik untuk [[CERN]]: atas, kabel biasa bagi [[LEP]]; bawah, kabel superkonduktif bagi [[Large Hadron Collider|LHC]].]]
Cara yang paling mudah adalah mengukur rintangan elektrik satu superkonduktor dengan meletakkannya di dalam [[litar elektrik]], dalam siri-siri dengan satu punca voltan (perbezaan keupayaan) ''V'' (contohnya satu [[bateri]]), dan ukur arus yang dihasilkannya. Sekiranya rintangan unsur-unsur arus (seperti plumbum yang berkait dengan sampel kepada litar berkenaan, dan [[rintangan dalaman]]) adalah ''R'', arus yang mengalir menerusi sampel adalah ''V/R''. Berdasarkan [[Hukum Ohm]], ini bermakna rintangan sampel superkonduktor adalah sifar.
Superconductivity is an essentially [[quantum mechanics|quantum mechanical]] phenomenon, and cannot be understood simply as the idealization of "[[perfect conductor|perfect conductivity]]" in classical physics.
Superconductors are also able to maintain a current with no applied voltage whatsoever, a property exploited in superconducting [[electromagnet]]s such as those found in [[Magnetic resonance imaging|MRI]] machines. Experiments have demonstrated that currents in superconducting coils can persist for years without any measurable degradation. Experimental evidence points to a current lifetime of at least 100,000 years, and theoretical estimates for the lifetime of persistent current exceed the lifetime of the universe.
In a normal conductor, an electrical current may be visualized as a fluid of electrons moving across a heavy [[ion]]ic lattice. The electrons are constantly colliding with the ions in the lattice, and during each collision some of the [[energy]] carried by the current is absorbed by the lattice and converted into [[heat]] (which is essentially the vibrational [[kinetic energy]] of the lattice ions.) As a result, the energy carried by the current is constantly being dissipated. This is the phenomenon of electrical resistance.
==External links==
The situation is different in a superconductor. In a conventional superconductor, the electronic fluid cannot be resolved into individual electrons, instead consisting of bound ''pairs'' of electrons known as [[Cooper pair]]s. This pairing is caused by an attractive force between electrons from the exchange of [[phonon]]s. Due to [[quantum mechanics]], the [[energy spectrum]] of this Cooper pair fluid possesses an ''energy gap'', meaning there is a minimum amount of energy ''ΔE'' that must be supplied in order to excite the fluid. Therefore, if ''ΔE'' is larger than the thermal energy of the lattice (given by ''kT'', where ''k'' is [[Boltzmann's constant]] and ''T'' is the temperature), the fluid will not be scattered by the lattice. The Cooper pair fluid is thus a [[superfluid]], meaning it can flow without energy dissipation.
In a class of superconductors known as type II superconductors (including all known high-temperature superconductors), an extremely small amount of resistivity appears at temperatures not too far below the nominal superconducting transition when an electrical current is applied in conjunction with a strong magnetic field (which may be caused by the electrical current). This is due to the motion of vortices in the electronic superfluid, which dissipates some of the energy carried by the current. If the current is sufficiently small, the vortices are stationary, and the resistivity vanishes. The resistance due to this effect is tiny compared with that of non-superconducting materials, but must be taken into account in sensitive experiments. However, as the temperature decreases far enough below the nominal superconducting transition, these vortices can become frozen into a disordered but stationary phase known as a "vortex glass". Below this vortex glass transition temperature, the resistance of the material becomes truly zero.
===Peralihan fasa Superkonduktor===
[[Image:Cvandrhovst.png|thumb|right|Kelakuan muatan haba (c<sub>v</sub>) dan kerintangan (ρ) pada peralihan fasa superkonduktor]]
In superconducting materials, the characteristics of superconductivity appear when the temperature ''T'' is lowered below a '''critical temperature''' ''T<sub>c</sub>''. The value of this critical temperature varies from material to material. Conventional superconductors usually have critical temperatures ranging from less than 1 K to around 20 K. Solid [[Mercury (element)|mercury]], for example, has a critical temperature of 4.2 K. [[As of 2001]], the highest critical temperature found for a conventional superconductor is 39 K for [[magnesium diboride]] (MgB<sub>2</sub>), although this material displays enough exotic properties that there is doubt about classifying it as a "conventional" superconductor. Cuprate superconductors can have much higher critical temperatures: YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7</sub>, one of the first cuprate superconductors to be discovered, has a critical temperature of 92 K, and mercury-based cuprates have been found with critical temperatures in excess of 130 K. The explanation for these high critical temperatures remains unknown. (Electron pairing due to phonon exchanges explains superconductivity in conventional superconductors, but it does not explain superconductivity in the newer superconductors that have a very high ''T''<sub>''c''</sub>.)
The onset of superconductivity is accompanied by abrupt changes in various physical properties, which is the hallmark of a [[phase transition]]. For example, the electronic heat capacity is proportional to the temperature in the normal (non-superconducting) regime. At the superconducting transition, it suffers a discontinuous jump and thereafter ceases to be linear. At low temperatures, it varies instead as ''e''<sup>−α/''T''</sup> for some constant α. (This exponential behavior is one of the pieces of evidence for the existence of the energy gap.)
The order of the superconducting phase transition is still a matter of debate. It had long been thought that the transition is second-order, meaning there is no [[latent heat]]. However, recent calculations have suggested that it may actually be weakly first-order due to the effect of long-range fluctuations in the electromagnetic field.
===Kesan Meissner===
When a superconductor is placed in a weak external [[magnetic field]] '''H''', the field penetrates the superconductor for only a short distance ''λ'', called the '''penetration depth''', after which it decays rapidly to zero. This is called the '''Meissner effect''', and is a defining characteristic of superconductivity. For most superconductors, the penetration depth is on the order of 100 nm.
The Meissner effect is sometimes confused with the kind of [[diamagnetism]] one would expect in a perfect electrical conductor: according to [[Lenz's law]], when a ''changing'' magnetic field is applied to a conductor, it will induce an electrical current in the conductor that creates an opposing magnetic field. In a perfect conductor, an arbitrarily large current can be induced, and the resulting magnetic field exactly cancels the applied field.
The Meissner effect is distinct from this because a superconductor expels ''all'' magnetic fields, not just those that are changing. Suppose we have a material in its normal state, containing a constant internal magnetic field. When the material is cooled below the critical temperature, we would observe the abrupt expulsion of the internal magnetic field, which we would not expect based on Lenz's law.
The Meissner effect was explained by London and London, who showed that the electromagnetic [[free energy]] in a superconductor is minimized provided
:<math> \nabla^2\mathbf{H} = \lambda^{-2} \mathbf{H}\, </math>
where '''H''' is the magnetic field and λ is the penetration depth.
This equation, which is known as the [[London equation]], predicts that the magnetic field in a superconductor [[exponential decay|decays exponentially]] from whatever value it possesses at the surface.
The Meissner effect breaks down when the applied magnetic field is too large. Superconductors can be divided into two classes according to how this breakdown occurs. In '''Type I''' superconductors, superconductivity is abruptly destroyed when the strength of the applied field rises above a critical value ''H<sub>c</sub>''. Depending on the geometry of the sample, one may obtain an '''intermediate state''' consisting of regions of normal material carrying a magnetic field mixed with regions of superconducting material containing no field. In '''Type II''' superconductors, raising the applied field past a critical value ''H''<sub>''c''1</sub> leads to a '''mixed state''' in which an increasing amount of magnetic flux penetrates the material, but there remains no resistance to the flow of electrical current as long as the current is not too large. At a second critical field strength ''H''<sub>''c''2</sub>, superconductivity is destroyed. The mixed state is actually caused by vortices in the electronic superfluid, sometimes called [[fluxons]] because the flux carried by these vortices is [[quantum|quantized]]. Most pure [[chemical element|element]]al superconductors (except [[niobium]], [[technetium]], [[vanadium]] and [[carbon nanotube]]s) are Type I, while almost all impure and compound superconductors are Type II.
==Teori-teori superkonduktor==
Since the discovery of superconductivity, great efforts have been devoted to finding out how and why it works. During the [[1950]]s, theoretical condensed matter physicists arrived at a solid understanding of "conventional" superconductivity, through a pair of remarkable and important theories: the phenomenological [[Ginzburg-Landau theory]] ([[1950]]) and the microscopic [[BCS theory]] ([[1957]]). Generalizations of these theories form the basis for understanding the closely related phenomenon of [[superfluidity]] (because they fall into the [[Lambda transition]] universality class), but the extent to which similar generalizations can be applied to unconventional superconductors as well is still controversial.
==Sejarah superkonduktor==
''Artikel : [[Sejarah superkonduktor]]''
Superconductivity was discovered in [[1911]] by [[Heike Kamerlingh Onnes]], who was studying the resistivity of solid [[mercury (element)|mercury]] at cryogenic temperatures using the recently-discovered liquid [[helium]] as a refrigerant. At the temperature of 4.2 K, he observed that the resistivity abruptly disappeared. For this discovery, he was awarded the [[Nobel Prize in Physics]] in [[1913]].
In subsequent decades, superconductivity was found in several other materials. In [[1913]], [[lead]] was found to superconduct at 7 K, and in [[1941]] niobium nitride was found to superconduct at 16 K.
The next important step in understanding superconductivity occurred in [[1933]], when [[Walter Meissner|Meissner]] and [[Robert Ochsenfeld|Ochsenfeld]] discovered that superconductors expelled applied magnetic fields, a phenomenon which has come to be known as the [[Meissner effect]]. In [[1935]], F. and H. London showed that the Meissner effect was a consequence of the minimization of the electromagnetic [[free energy]] carried by superconducting current.
In [[1950]], the phenomenological [[Ginzburg-Landau theory]] of superconductivity was devised by [[Lev Davidovich Landau|Landau]] and [[Vitalij Lazarevics Ginzburg|Ginzburg]]. This theory, which combined Landau's theory of second-order [[phase transition]]s with a [[Schrödinger equation|Schrödinger]]-like wave equation, had great success in explaining the macroscopic properties of superconductors. In particular, [[Alexei Alexeevich Abrikosov|Abrikosov]] showed that Ginzburg-Landau theory predicts the division of superconductors into the two categories now referred to as Type I and Type II. Abrikosov and Ginzburg were awarded the [[2003]] Nobel Prize for their work (Landau having died in [[1968]].)
Also in [[1950]], Maxwell and Reynolds ''et. al.'' found that the critical temperature of a superconductor depends on the [[isotope|isotopic mass]] of the constituent [[chemical element|element]]. This important discovery pointed to the electron-phonon interaction as the microscopic mechanism responsible for superconductivity.
The complete microscopic theory of superconductivity was finally proposed in [[1957]] by [[John Bardeen|Bardeen]], [[Leon Neil Cooper|Cooper]], and [[John Robert Schrieffer|Schrieffer]]. Independently superconductivity phenomenon was explained by [[Nikolay Bogolyubov]]. This [[BCS theory]] explained the superconducting current as a superfluid of [[Cooper pair]]s, pairs of electrons interacting through the exchange of phonons. For this work, the authors were awarded the Nobel Prize in [[1972]].
The BCS theory was set on a firmer footing in [[1958]], when Bogoliubov showed that the BCS wavefunction, which had originally been derived from a variational argument, could be obtained using a canonical transformation of the electronic [[Hamiltonian (quantum mechanics)|Hamiltonian]]. In [[1959]], Gor'kov showed that the BCS theory reduced to the Ginzburg-Landau theory close to the critical temperature.
In [[1962]], the first commercial superconducting wire, a niobium-titanium alloy, was developed by researchers at [[Westinghouse Electric Corporation|Westinghouse]]. In the same year, [[Brian David Josephson|Josephson]] made the important theoretical prediction that a supercurrent can flow between two pieces of superconductor separated by a thin layer of insulator. This phenomenon, now called the [[Josephson effect]], is exploited by superconducting devices such as [[SQUID]]s. It is used in the most accurate available measurements of the [[magnetic flux quantum]] ''h/e'', and thus (coupled with the [[quantum Hall effect|quantum Hall resistivity]]) for [[Planck's constant]] ''h''. Josephson was awarded the Nobel Prize for this work in [[1973]].
Until [[1986]], physicists had believed that BCS theory forbade superconductivity at temperatures above about 30 K. In that year, [[Johannes Georg Bednorz|Bednorz]] and [[Karl Alexander Müller|Müller]] discovered superconductivity in a [[lanthanum]]-based cuprate perovskite material, which had a transition temperature of 35 K (Nobel Prize in Physics, [[1987]]). It was shortly found by Paul C. W. Chu of the University of Houston and M.K. Wu at the [[University of Alabama in Huntsville]] [http://64.233.161.104/search?q=cache:Ld0r1qeeJNgJ:www.the-scientist.com/yr1988/jul/letters_p14_880711.html+Huntsville++%22paul+chu%22&hl=en] that replacing the lanthanum with [[yttrium]], i.e. making [[YBCO]], raised the critical temperature to 92 K, which was important because [[liquid nitrogen]] could then be used as a refrigerant (at atmospheric pressure, the boiling point of nitrogen is 77 K.) This is important commercially because liquid nitrogen can be produced cheaply on-site with no raw materials, and is not prone to some of the problems (solid air plugs, etc) of [[liquid helium|helium]] in piping. Many other cuprate superconductors have since been discovered, and the theory of superconductivity in these materials is one of the major outstanding challenges of theoretical [[condensed matter physics]]. Recently, there has been research citing that a room temperature superconductor may exist within today's technological standards. This material is metallic hydrogen, and at high pressures, it displays some superconductive properties. Therefore, some scientists have concluded that a room temperature superconductor has been created, however, it is under great controversy.
==Aplikasi superkonduktor pada teknologi==
There have been many technological innovations based on superconductivity. Superconductors are used to make some of the most powerful [[electromagnet]]s known to man, including those used in [[magnetic resonance imaging|MRI]] machines and the beam-steering magnets used in [[particle accelerator]]s. Another application is for magnetic separation where weakly magnetic particles are extracted from a background of less or non-magnetic particles (used in a large scale in pigment industries).
Superconductors have also been used to make [[digital circuit]]s (e.g. based on the [[Rapid single flux quantum|Rapid Single Flux Quantum]] technology) and [[microwave]] filters for [[mobile phone]] base stations.
Superconductors are used to build [[Josephson junction]]s which are the building blocks of [[SQUID]]s (superconducting quantum interference devices), the most sensitive [[magnetometer]]s known. Series of Josephson devices are used to define the SI [[volt]]. Depending on the particular mode of operation, a [[Josephson junction]] can be used as photon [[detector]] or as [[mixer]]. The large resistance change at the transition from the normal- to the superconducting state is used to build thermometers in cryogenic [[calorimeter|micro-calorimeter]] photon [[detector]]s.
Many promising applications of superconductivity have been stalled by the impracticality of maintaining large systems (e.g. long stretches of cable) at cryogenic temperatures. These problems may soon be alleviated with the continued development of high temperature superconductors (HTS), as these can be cooled by using liquid nitrogen rather than liquid helium (which is much more expensive and difficult to handle) or by using [[cryocooler]]s. However, the currently known high-temperature superconductors are brittle ceramics which are expensive to manufacture and not easily turned into wires or other useful shapes.
However commercial quantities of HTS wire based on [[BSCCO]] are now available at around 5 times the price of the equivalent copper conductor. BSCCO wire requires a batch production process and relatively high quantites of silver, and so is inherently expensive to produce. Pilot plants are being developed that use YBCO to produce coated conductors in a semi-continuous process. Manufacturers are claiming the potential to reduce the price in volume to 50% to 20% of BSCCO. If the latter occurs HTS wire will be competitive with copper in all large industrial applications.
Right now HTS wire is used in current leads for low temperature superconducting devices. Early markets for the wire are emerging in replacing low temperature superconductors (LTS) in powerful magnets (copper has a limit to the field strength it can produce, and while HTS wire is much more expensive than LTS this can be offset by the relative cost and convenience of cooling).
Other early markets are arising where the relative efficiency, size and weight advantages of devices based on HTS outweigh the additional costs involved.
Promising future applications include high-performance [[transformer]]s, [[SMES|power storage devices]], [[electric power transmission]], [[electric motor]]s (e.g. for vehicle propulsion, as in [[vactrain]]s or [[Maglev train|maglev trains]]), [[magnetic levitation device]]s, and [[Fault Current Controllers]]. However superconductivity is sensitive to moving magnetic fields so applications that use [[alternating current]] (e.g. transformers) will be more difficult to develop than those that rely upon [[direct current]].
==Superkonduktor pada budaya popular==
Superconductivity has long been a staple of [[science fiction]]. One of the first mentions of the phenomenon occurred in [[Robert A. Heinlein]]'s novel ''[[Beyond This Horizon]]'' ([[1942]]). Notably, the use of a fictional [[room temperature superconductor]] was a major plot point in the ''[[Ringworld]]'' novels by [[Larry Niven]], first published in [[1970]].
Superconductivity is a popular device in science fiction due to the simplicity of the underlying concept - zero electrical resistance - and the rich technological possibilities. For example, superconducting magnets could be used to generate the powerful [[magnetic field]]s used by [[Bussard ramjet]]s, a type of spacecraft commonly encountered in science fiction. The most troublesome property of real superconductors, the need for cryogenic cooling, is often circumvented by postulating the existence of room temperature superconductors. Many stories attribute additional properties to their fictional superconductors, ranging from infinite heat conductivity in Niven's novels (real superconductors conduct heat poorly, though superfluid [[helium]] has immense but finite heat conductivity) to providing power to an interstellar travel device in the [[Stargate]] [[Stargate (film)|movie]] and [[Stargate SG-1|TV series]].
In the movie ''[[Terminator 2: Judgment Day]]'', the CPU of the T-800 destroyed in Terminator 1 is found to be superconductive at room temperature.
Superconductors are a technology required in the acclaimed [[Civilization (computer game)|Civilization series (computer game)]] in order to build the spaceship to [[Alpha centauri]] hence achieving a space victory.
==Lihat juga==
* [[BCS theory]]
* [[SQUID]]
* [[Timeline of low-temperature technology]]
* [[Organic superconductor]]s
* [[Homes's law]]
* [[Charge transfer complex]]
* [[Spallation Neutron Source]]
* [[Proximity effect#Superconducting proximity effect|Proximity effect]]
* [[Josephson effect]]
* [[Superfluidity]]
==Rujukan==
===Buku-buku===
*{{cite book | author=Tinkham, Michael | title=Introduction to Superconductivity | edition = 2<sup>nd</sup> ed. | publisher=Dover Books on Physics | year=2004 | id=ISBN 0486435032 (Paperback)}}
*{{cite book | author=Tipler, Paul; Llewellyn, Ralph | title=Modern Physics | edition = 4<sup>th</sup> ed. | publisher=W. H. Freeman | year=2002 | id=ISBN 0716743450}}
===Artikel-artikel journal===
* {{cite journal
| author = H.K. Onnes
| title = <!-- unknown -->
| journal = Commun. Phys. Lab.
| volume = 12
| issue = 120
| year = 1911
}}
* {{cite journal
| author = W. Meissner and R. Oschenfeld
| title = <!-- unknown -->
| journal = Naturwiss.
| volume = 21
| issue = 787
| year = 1933
}}
* {{cite journal
| author = F. London and H. London
| title = <!-- unknown -->
| journal = Proc. R. Soc. London
| volume = A149
| issue = 71
| year = 1935
}}
* {{cite journal
| author = V.L. Ginzburg and L.D. Landau
| title = <!-- unknown -->
| journal = Zh. Eksp. Teor. Fiz.
| volume = 20
| issue = 1064
| year = 1950
}}
* {{cite journal
| author = E.Maxwell
| title = <!-- unknown -->
| journal = Phys. Rev.
| volume = 78
| issue = 477
| year = 1950
}}
* {{cite journal
| author = C.A. Reynolds ''et. al.''
| title = <!-- unknown -->
| journal = Phys. Rev.
| volume = 78
| issue = 487
| year = 1950
}}
* {{cite journal
| author = J. Bardeen, L.N. Cooper, and J.R. Schrieffer
| title = <!-- unknown -->
| journal = Phys. Rev.
| volume = 108
| issue = 1175
| year = 1957
}}
* {{cite journal
| author = N.N. Bogoliubov
| title = <!-- unknown -->
| journal = Zh. Eksp. Teor. Fiz.
| volume = 34
| issue = 58
| year = 1958
}}
* {{cite journal
| author = L.P. Gor'kov
| title = <!-- unknown -->
| journal = Zh. Eksp. Teor. Fiz.
| volume = 36
| issue = 1364
| year = 1959
}}
* {{cite journal
| author = B.D. Josephson
| title = <!-- unknown -->
| journal = Phys. Lett.
| volume = 1
| issue = 251
| year = 1962
}}
* {{cite journal
| author = J.G. Bednorz and K.A. Mueller
| title = <!-- unknown -->
| journal = Z. Phys.
| volume = B64
| issue = 189
| year = 1986
}}
* {{cite journal
| author = M. K. Wu, J. R. Ashburn, C. J. Torng, P. H. Hor, R. L. Meng, L. Gao, Z. J. Huang, Y. Q. Wang, and C. W. Chu
| title = Superconductivity at 93 K in a New Mixed-Phase Y-Ba-Cu-O Compound System at Ambient Pressure
| journal = Physical Review Letters
| year = 1987 | volume = 58
| pages = 908–910
}}
==Pautan luar==
*[http://www.eere.energy.gov/EE/power_superconductivity.html US, EREN: superconductivity]
*[http://www.superconductors.org/ superconductors.org]
*[http://www.ornl.gov/reports/m/ornlm3063r1/pt1.html Introduction to superconductivity]
*[http://www.sns.gov/partnerlabs/jlab.htm Superconducting Niobium Cavities]
*[http://www.ornl.gov/sci/fed/applied/ Superconductivity] at [[Oak Ridge National Laboratory]]
*[http://www.superlife.info Superconductivity in everyday life : Interactive exhibition]
*[http://web.njit.edu/~mathclub/superconductor/index.html Video of the Meissner effect from the NJIT Mathclub]
*[http://fhqed.free.fr/supra/supracond.htm Play with a Superconductor !]
*[http://www.superconductorweek.com Superconductor Week Newsletter - industry news, links, etc]
*[http://www.iop.org/EJ/journal/SUST '''Superconductor Science and Technology''']
==Media==
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{{multi-video item|filename=Flyingsuperconductor.ogg|title=Superconducting levitation of YBCO|description=Video of superconducting levitation of YBCO (360[[Kilobyte|KB]], [[Ogg]]/[[Theora]] format).|format=[[Theora]]}}
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