Geometry.Net - Basic_S: Superconductors

Materials Chemistry - Superconductors
superconductors are also perfectly diamagnetic (ie they repel a magnetic field);this property was discovered in 1933 and named the Meissner effect.
http://imr.chem.binghamton.edu/labs/super/superc.html

Extractions: Figure 1. Electrical resistance of a superconductor. Superconductors are also perfectly diamagnetic (i.e. they repel a magnetic field); this property was discovered in 1933 and named the Meissner effect This compound is often called the 1 2 3 material from the molar ratios of Y:Ba:Cu. The heating-cooling synthesis sequence is shown graphically in figure 2.
English Books > Technical > Superconductors & Superconductivity
Books Technical superconductors Superconductivity Index of 58 Titles.AC Losses And Flux Pinning In High Temperature superconductors
http://book.netstoreusa.com/index/bkbtd900.shtml
Organic Superconductors
Organic superconductors. The following compounds are all from thelaboratory of Prof. LK Montgomery. His laboratory has an active
http://www.iumsc.indiana.edu/dataindices/organic_superconductors.html

Extractions: The following compounds are all from the laboratory of Prof. L. K. Montgomery . His laboratory has an active program studying the physical properties of compounds that are known or suspected to possess superconducting properties. The following complexes have been synthesized over the past few years. Most consist of a carbocation containing sulfur and/or selenium in a ring system and one or more anions. For information on these, contact Prof. Montgomery at montgome@indiana.edu . You can read about other organic chemistry research at Indiana University in the Organic Chemistry pages of the departmental web site. Formula: [C10H8S4Se4]2 [GaCl4] Formula: [C10H8S4Se4]2 cu(N(CN)2]Br Formula: [C10H8S4Se4]2 [CF3SO3] Formula: [C10H8S4Se4]2 [SbF6] Formula: [C10H8S4Se4]2 [SbF6] Formula: [C10H8S4Se4]2 [GaCl4] Formula: [C10H8Se4S4]2 [CF3SO3] Formula: [C10H8S4Se4]2 Cu[N(CN)2Br] Formula: [C10H8Se8S8]3 [GaCl4] [C2H3Cl3] Formula: [C10H8S4Se4]2 [GaCl4] Formula: [C10H8S4Se4]2 [GaCl4] Formula: 2[BETS] [GaCl4] Formula: [C6H8S4]+ [SbF6]- Formula: [C10H8Se8S8]2 [CF3SO3] Formula: [C10H8S8]2 [GaCl4] Formula: [C10H8S8]2 [GaCl4] Formula: [C10H8S4Se4]2 [TlI4] [I3] Formula: [C6H8S4]+ [AsF6]- Formula: [C10H8S8]2 [GaCl4] Formula: [C10H8Se4S4]2 [Hg(SCN)4] [NH4] Formula: 4[C10H8S4Se4] [Hg3I8] Formula: [C10H8S8]2[NH4][Hg(SCN)4] Formula: 2[C10H8Se4S4] [Hg(SCN)4] [NH4] Formula: [C6H8S4] [AsF6]
APS News Online - Woodstock West: Celebrating The New MgB2 Superconductors
email apsnews. email webmaster. Woodstock West Celebrating the New MgB2 superconductors.Jun Akimitsu makes a point as session cochair John Clarke looks on.
http://www.aps.org/apsnews/0501/050101.html

Extractions: webmaster Jun Akimitsu makes a point as session co-chair John Clarke looks on. [Photo by Antonio Bianconi] The excitement was palpable in the Grand Ballroom at the Westin Hotel in Seattle on Monday night, March 12, as physicists, attending the APS March Meeting from around the world, gathered for a mammoth technical session discussing the discovery and subsequent experimental results on the newly discovered superconducting compound magnesium diboride (MgB ), first discovered less than two months ago in a laboratory in Japan. Speakers flew in from Japan, Korea, Switzerland, Italy, Britain, China, France, the Netherlands and Germany, in addition to numerous speakers from the US. A total of 79 ultra-short (2-minute) papers were presented, with the session running past one the following morning. It was quickly dubbed "Woodstock West," in memory of the so-called "Woodstock of Physics" at the 1987 APS March Meeting where the discovery of high-temperature superconductivity was first announced. Like many historical breakthroughs in science, the compound's discovery was partially serendipitous (although this was not the view of the discoverers-see Members in the Media). Jun Akimitsu's research group at Aoyama-Gakuin University in Tokyo were attempting to make a chemical analogue of CaB
Magneto-Optical Imaging Of Superconductors
physical principles and applications of magnetooptical imaging for characterizationof superconductors. Basic Properties of superconductors. Meissner effect.
http://www.fys.uio.no/super/mo/

Extractions: To be able to see magnetism directly with your eyes has been a very old dream. In a way magneto-optical imaging is the realization of that dream: you stick your sample under the microscope, put a piece of a magic crystal on top of it, and can through the ocular follow the sample's magnetic behaviour in real-time Links The physical idea behind the magneto-optical imaging is the Faraday effect , i.e., rotation of the light polarization induced by magnetic field. On 13 September, 1845, Michael Faraday wrote in his Diary "...magnetic force and light were proved to have relation to each other. This fact will most likely prove exceedingly fertile and of great value in the investigation of both conditions of natural force" A number of different materials have been applied as indicators in MO imaging: cerous nitrate-glycerol , various europium compounds (EuS, EuSe) [H. Kirchner, Phys. Lett. 26A, 651 (1968)]
JC Davis Group, University Of California At Berkeley
Conventional superconductors. These materials are called superconductors and theycan conduct electricity without any loss of energy into unwanted heating.
http://www.ccmr.cornell.edu/~jcdavis/stm/background/SCbackground.htm
QuickField Support Site: Features: Applications: Superconductors
QuickField logo Applications.
http://www.quickfield.com/app_super.htm

Extractions: The table below shows the QuickField packages that can be applied to the various aspects of superconducting system design. Click on an option to read more about each feature: Option Design field DC magnetics Magnetic field and flux distribution. Simulation of the field penetration into a real superconductor. Calculation of magnetic forces and torques. We are ready to answer any questions or provide you with Professional version purchase terms.
High Temperature Superconductors
High Temperature superconductors. Our department has an experimentalresearch effort in the area of lowtemperature physics, with
http://phys.kent.edu/pages/cep.htm

Extractions: High Temperature Superconductors Our department has an experimental research effort in the area of low-temperature physics, with emphasis on the study of the transport and magnetic behaviors of the high temperature superconductors. The picture at the right [from A. Sleight, Science 1519 (1988)] shows the structure of a typical such material. The high temperature superconductors represent a new class of materials which bear extraordinary superconducting and magnetic properties and great potential for wide-ranging technological applications. The importance of understanding the transport and magnetic behaviors of these novel materials is two-fold. First, it could lead to a better understanding of the basic phenomena of superconductivity in these materials. Second, it could provide ways to improve the magnetic quality of the presently known materials by enhancing flux pinning in a controllable manner. A current-carrying type II When a current is applied to a type II superconductor (blue rectangular box) in the mixed state, the magnetic vortices (blue cylinders) feel a force (Lorentz force) that pushes the vortices at right angles to the current flow. This movement dissipates energy and produces resistance [from D. J. Bishop et al., Scientific American, 48 (Feb. 1993)]. When a type II superconductor is placed in a magnetic field H < H < H , where H and H are the lower and upper critical fields, respectively, the magnetic vortices that penetrate the material should form a uniform triangular lattice (Abrikosov vortex lattice) with a lattice spacing determined by the strength of H. If H is increased, the vortices become more closely spaced and their cores start to overlap. At H
Flux Lines In Type II Superconductors
next up previous contents Next Relation to surface growth Up Directed polymersPrevious Directed polymers. Flux lines in type II superconductors.
http://online.itp.ucsb.edu/online/lnotes/balents/node18.html

Extractions: Next: Relation to surface growth Up: Directed polymers Previous: Directed polymers In a type II superconductor, an external magnetic field applied to a sample penetrates in the form of quantized bundles of flux, known as flux or vortex lines[ ]. These flux bundles are in fact topological defects very analogous to domain walls in Ising magnets. In the case of the superconductor, the order parameter is the complex ``pair wavefunction'' or gap The macroscopic properties of most superconductors are well described by a phenomenological expansion of the free energy in coupled to the electro-magnetic field, known as Ginzburg-Landau theory where is the superconducting flux quantum. The factor of 2 e in reflects the charge of the singlet pair. In the ordered phase at low temperatures, the coefficient is large and negative, and develops an almost uniform amplitude. . The phase, however, can still vary in space, Up to a constant, the free energy becomes A vortex is a configuration of which winds by around some closed loop enclosing a singularity in the phase field (a singularity is necessary since the phase must wind even as one shrinks the path to a point). In three dimensions, these singularities take the form of lines.
Superconductors
The magnetic properties exhibited by superconductors are just as dramatic. Allelemental and alloy superconductors are swave BCS superconductors 4.
http://www.phys.warwick.ac.uk/supermag/Research/Superconductors/body_superconduc

Extractions: A brief history of superconductivity The phenomenon of superconductivity was first observed by Kamerlingh Onnes in Leiden in 1911 . In the superconducting state the dc electrical resistivity is zero Heike Kamerlingh Onnes, was awarded the Nobel Prize in 1913 for his discovery of superconductivity The magnetic properties exhibited by superconductors are just as dramatic. If a type I superconductor is placed in a magnetic field below a critical value H c , then cooled through its superconducting transition temperature, (T c ), the magnetic flux originally present in the sample is ejected from the specimen. This is called the Meissner effect A magnet floating above a disc of ceramic superconductor due to a combination of flux pinning and flux expulsion. If a type II superconductor is cooled below T c ), it will also enter the Meissner state. For fields above the lower critical field H but below an upper critical field H , (H ), type II superconductors enter a mixed state in which the material is threaded by an array of lines of magnetic flux forming an Abrikosov or flux line lattice The hexagonal arrangement of magnetic flux lines in pure Nb imaged using neutrons.
LOM Superconductors
Structural and physical properties relations of high temperaturesuperconductors with a focus on mercury cuprates. Grant Agency
http://www.fzu.cz/departments/mgsupcond/lom/supra.html

Extractions: The aim of the project is to find optimum conditions for the mercury superconductors preparation in the form of ceramic materials as well as thin films. In the first it is the preparation of homogeneous and reactive precursors by the sol-gel method. Then it is the final synthesis in the closed system, sealed silica tubes, where the oxygen and mercury partial pressures can be adjusted by suitable agents with a help of multizone furnace. Appropriate partial pressures will be searched experimentally and by thermodynamic calculations. The semiempirical approach will be employed to analyse the relations between the superconducting and structural properties influenced by replacing of mercury by various cations and barium by strontium. Selected papers Calorimetric Determination of Enthalpy and Entropy of Formation of HgAO2 (A = Ba, Sr, Ca) Phases
Structure And Arrangement Of Vortices In Superconductors
Structure and Arrangement of Vortices in superconductors. 37 April2002, Prague. Scope. This workshop will focus on the structure
http://www.fzu.cz/activities/workshops/vortex/

Extractions: Vortices in Superconductors This workshop will focus on the structure and arrangement of vortices in conventional and unconventional superconductors. Vortex structure, vortex dynamics, forces acting on vortices, vortex core and its dynamic distortions, induced electric fields as well as vortex imaging techniques are the main topics to be touched. Nano-engineered artificial pinning centers as well as vortex properties in artificially made structures such as multilayers, arrays and mesoscopic samples will be also discussed. Pre-registration 5 January 2002
NRL - High Temperature Superconducting Space Experiment
positioning image, / NRL / Accomplishments / Materials / Hi Temp superconductors.High Temperature Superconducting Space Experiment.
http://www.nrl.navy.mil/content.php?P=HTSUPERCOND
The High Temperature Superconductors
The High Temperature superconductors. Within the next six years a number ofadditional families of high temperature superconductors were discovered.
http://cnls.lanl.gov/Highlights/1997-06/html/node4.html

Extractions: Next: Nearly Antiferromagnetic Fermi Liquid Up: Understanding High Temperature Previous: BCS Theory and Its A new era in superconductivity opened when, on January 27, 1986, Bednorz and Mueller discovered a sharp drop in the resistance of La Ba CuO Cu O , which possessed a of over 90K. Thus within a year of the original discovery the superconducting transition temperature had increased by a factor of three, and it was clear that a revolution in superconductivity had begun. A celebration of the start of that new era took place at a special evening session of the American Physical Society's 1987 March meeting in New York City, when some 3000 physicists jammed the auditorium in which the session took place, with another 3000 people watching on closed circuit television outside, an event which has become known as the Woodstock of Physics. Within the next six years a number of additional families of high temperature superconductors were discovered. These included Tl- and Hg- based systems which had maximum 's of 120K and 160K respectively. All shared the feature which appeared responsible for the occurrence of high temperature superconductivity, the presence of planes containing Cu and O atoms which are separated by bridging materials which act as charge reservoirs for the planes. During this period, some 10,000 papers a year were being published on high temperature superconductors (a pace which continues to the present time) and it became evident that high temperature superconductivity was regarded by many as the major problem in physics in the last decade of this century. There are at least four reasons for the extraordinary interest in high
Conventional Superconductors: From Discovery To Understanding
Understanding High Temperature Previous Introduction. Conventionalsuperconductors From Discovery to Understanding. In his 1913 Nobel
http://cnls.lanl.gov/Highlights/1997-06/html/node2.html

Extractions: From Discovery to Understanding In his 1913 Nobel lecture, Kamerlingh-Onnes reported that ``mercury at 4.2K has entered a new state, which owing to its particular electrical properties, can be called the state of superconductivity.'' He noted that the state could be destroyed by applying a sufficiently large magnetic field, while a current induced in a closed loop of superconducting wire persisted for an extraordinarily long time. He demonstrated the latter phenomenon by starting a superconducting current in a coil in his Leiden laboratory, then transporting the coil, plus the ``refrigerator'' which kept it cold, to Cambridge University for a lecture-demonstration on superconductivity. is very large compared to their average thermal energy, kT . As a result, only a fraction of the electrons, , are excited above the ground state. The electrons interact with each other (by Coulomb's law) and with the phonons. Their elementary excitations are quasiparticles, the electrons plus their associated cloud of other electrons and phonons which accompany electrons as they move through the lattice. An elementary argument shows that the lifetime of a quasiparticle excited above the Fermi surface (the surface of the Fermi sphere) is some . The problem faced by the theorists was understanding how these interacting electrons could undergo a transition to the superconducting state. What brought it about? What was the appropriate mathematical description?
EBooks.com - Superconductors & Superconductivity
Home Technology superconductors Superconductivity. You haveselected the Subject of superconductors Superconductivity. The
http://www.ebooks.com/subjects/subjects.asp?SID=1218
Begell House, Inc. - The Physics Of Composite Superconductors
The Physics of Composite superconductors AV Gurevich 1 RG Mints 2AL Rakhmanov 1 1 Russian Academy of Sciences, Moscow, Russia 2
http://www.begellhouse.com/properties/composite_super.html
Superconductors
superconductors Will They Reshape the Electric Grid? by Alan S. Brown.Fifteen years after their discovery, high-temperature superconductors
http://www.nfpa.org/nec/NECDigest/ArticleArchives/AugSept2002/Superconductors/Su

Extractions: by Alan S. Brown Fifteen years after their discovery, high-temperature superconductors - materials that conduct electricity without energy loss at temperatures above that of liquid nitrogen - are poised to enter real world electrical applications. Lights will not burn any brighter. Appliances will still plug into electrical sockets. In fact, most consumers will never notice the change. Yet they are going to cause considerable modifications when they tap into the electric grid, because they require an entirely new cooling infrastructure, as well as new types of terminations. They will also change site options for transformers and other types of equipment. High-temperature superconducting (HTS) power distribution cables promise to vastly increase the amount of current utilities can pump through existing inner city right-of-ways. Utilities may be able to double or even triple capacity without digging up streets. The entire article is available only in the print version of our magazine. Subscribe online for your FREE subscription NFPA (National Fire Protection Association)
Superconductors That Work At Room Temperature
superconductors that work at room temperature. Tiny water. The tubeswould be the first superconductors to work at room temperature.
http://www.globaltechnoscan.com/5thDec-11thDec01/superconductors.htm

Extractions: Superconductors that work at room temperature Tiny tubes of carbon may conduct electricity without any resistance, at temperatures stretching up past the boiling point of water. The tubes would be the first superconductors to work at room temperature. Guo-meng Zhao and Yong Sheng Wang of the University of Houston in Texas found subtle signs of superconductivity. It wasn't zero resistance, but it's the closest anyone's got so far. "I think all the experimental results are consistent with superconductivity," Zhao says. "But I cannot rule out other explanations." At the moment no superconductor will work above about 130 kelvin (-143 ¡C). But if a material could carry current with no resistance at room temperature, no energy would be lost as heat, meaning faster, lower-power electronics. And electricity could be carried long distances with 100 per cent efficiency. Zhao and Wang studied the effects of magnetic fields on hollow fibres of carbon known as "multiwall carbon nanotubes". Each nanotube is typically a millionth of a metre long, several billionths of a metre in diameter and with walls a few atoms thick. The nanotubes cling together in oblong bundles about a millimetre in length. The researchers did not see zero resistance in their bundles. They think this is because the connections between the tiny tubes never become superconducting. But they did see more subtle signs of superconductivity within the tubes themselves.
SRI: PSD's Superconductors
superconductors Ongoing research in superconductors at SRI has resulted in the design,construction, and testing of novel fluidizedbed CVD systems for high
http://www.sri.com/psd/research/superconductors.html

Extractions: Ongoing research in superconductors at SRI has resulted in the design, construction, and testing of novel fluidized-bed CVD systems for high rate deposition of thin films of high-temperature superconductors on wire substrates. SRI's design is less complex to implement and operate and costs less than conventional MOCVD systems. Fluidized-Bed CVD Reactor for Superconductor Deposition Reactor in Use Visit the Laboratory -

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