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Matthias Rules
In physics, the Matthias rules refers to a historical set of empirical guidelines on how to find superconductors. These rules were authored Bernd T. Matthias who discovered hundreds of superconductors using these principles in the 1950s and 1960s. Deviations from these rules have been found since the end of the 1970s with the discovery of unconventional superconductors. History Superconductivity was first discovered in solid mercury in 1911 by Heike Kamerlingh Onnes and Gilles Holst, who had developed new techniques to reach near-absolute zero temperatures. In subsequent decades, superconductivity was found in several other materials; In 1913, lead at 7 K, in 1930's niobium at 10 K, and in 1941 niobium nitride at 16 K. In 1933, Walther Meissner and Robert Ochsenfeld discovered that superconductors expelled applied magnetic fields, a phenomenon that has come to be known as the Meissner effect. Bernd T. Matthias and John Kenneth Hulm were encouraged by Enrico Fermi to st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physics
Physics is the scientific study of matter, its Elementary particle, fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular succession of events." It is one of the most fundamental scientific disciplines. "Physics is one of the most fundamental of the sciences. Scientists of all disciplines use the ideas of physics, including chemists who study the structure of molecules, paleontologists who try to reconstruct how dinosaurs walked, and climatologists who study how human activities affect the atmosphere and oceans. Physics is also the foundation of all engineering and technology. No engineer could design a flat-screen TV, an interplanetary spacecraft, or even a better mousetrap without first understanding the basic laws of physics. (...) You will come to see physics as a towering achievement of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enrico Fermi
Enrico Fermi (; 29 September 1901 – 28 November 1954) was an Italian and naturalized American physicist, renowned for being the creator of the world's first artificial nuclear reactor, the Chicago Pile-1, and a member of the Manhattan Project. He has been called the "architect of the nuclear age" and the "architect of the atomic bomb". He was one of very few physicists to excel in both theoretical physics, theoretical and experimental physics. Fermi was awarded the 1938 Nobel Prize in Physics for his work on induced radioactivity by neutron bombardment and for the discovery of transuranium elements. With his colleagues, Fermi filed several patents related to the use of nuclear power, all of which were taken over by the US government. He made significant contributions to the development of statistical mechanics, Quantum mechanics, quantum theory, and nuclear physics, nuclear and particle physics. Fermi's first major contribution involved the field of statistical mechanics. Afte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frank Steglich
Frank Steglich (born 14 March 1941) is a German physicist and the founding director of the Max Planck Institute for Chemical Physics of Solids in Dresden, Germany. Education and career Steglich was born in Dresden and studied physics in the University of Münster and the University of Göttingen, where he received his PhD under Rudolf Hilsch. Steglich discovered the first heavy fermion superconductor, CeCu2Si2, while working as a research associate in Cologne, Germany in 1979. CeCu2Si2 is the first metallic system to be discovered in which the superconductivity is driven by electron-electron interactions, rather than the electron-phonon interaction that is responsible for conventional BCS superconductivity. The discovery of this material revolutionized research into superconductivity, establishing the reality of electronically mediated superconductivity and foreshadowing the discovery of a wide range of heavy electron superconductors, and the subsequent discovery of electronica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heavy Fermion Superconductor
Heavy fermion superconductors are a type of unconventional superconductor. The first heavy fermion superconductor, CeCu2Si2, was discovered by Frank Steglich in 1978. Since then over 30 heavy fermion superconductors were found (in materials based on Ce, U), with a critical temperature up to 2.3 K (in CeCoIn5). Heavy fermion materials are intermetallic compounds, containing rare earth or actinide elements. The f-electrons of these atoms hybridize with the normal conduction electrons leading to quasiparticles with an enhanced effective mass. From specific heat measurements \Delta C/C(T_) one knows that the Cooper pairs in the superconducting state are also formed by the heavy quasiparticles. In contrast to normal superconductors it cannot be described by BCS theory In physics, the Bardeen–Cooper–Schrieffer (BCS) theory (named after John Bardeen, Leon Cooper, and John Robert Schrieffer) is the first microscopic theory of superconductivity since Heike Kamerlingh Onnes's 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selenide
A selenide is a chemical compound containing a selenium with oxidation number of −2. Similar to sulfide, selenides occur both as inorganic compounds and as organic derivatives, which are called organoselenium compound. Inorganic selenides The parent inorganic selenide is hydrogen selenide (H2Se). It is a colorless, malodorous, toxic gas. It dissolves in aqueous solution, to give the hydrogenselenide or biselenide ion HSe−. At higher pH, selenide forms. Solutions of hydrogen selenide and selenide are oxidized by air to give elemental selenium: : Most elements form selenides. They sometimes have salt-like properties, e.g. sodium selenide, but most exhibit covalent bonding, e.g. molybdenum diselenide. Their properties are diverse, mirroring the diverse properties of the corresponding sulfides. As indicated by the fact that only a few thousand tons of selenium are produced annually, the subset of selenium compounds called selenides find few applications. Commercially ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfide
Sulfide (also sulphide in British English) is an inorganic anion of sulfur with the chemical formula S2− or a compound containing one or more S2− ions. Solutions of sulfide salts are corrosive. ''Sulfide'' also refers to large families of inorganic and organic compounds, e.g. lead sulfide and dimethyl sulfide. Hydrogen sulfide (H2S) and bisulfide (HS−) are the conjugate acids of sulfide. Chemical properties The sulfide ion does not exist in aqueous alkaline solutions of Na2S. Instead sulfide converts to hydrosulfide: :S2− + H2O → SH− + OH− Upon treatment with an acid, sulfide salts convert to hydrogen sulfide: :S2− + H+ → SH− :SH− + H+ → H2S Oxidation of sulfide is a complicated process. Depending on the conditions, the oxidation can produce elemental sulfur, polysulfides, polythionates, sulfite, or sulfate. Metal sulfides react with halogens, forming sulfur and metal salts. :8 MgS + 8 I2 → S8 + 8 MgI2 Metal de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molybdenum
Molybdenum is a chemical element; it has Symbol (chemistry), symbol Mo (from Neo-Latin ''molybdaenum'') and atomic number 42. The name derived from Ancient Greek ', meaning lead, since its ores were confused with lead ores. Molybdenum minerals have been known throughout history, but the element was discovered (in the sense of differentiating it as a new entity from the mineral salts of other metals) in 1778 by Carl Wilhelm Scheele. The metal was first isolated in 1781 by Peter Jacob Hjelm. Molybdenum does not occur naturally as a Native metal, free metal on Earth; in its minerals, it is found only in oxidation state, oxidized states. The free element, a silvery metal with a grey cast, has the List of elements by melting point, sixth-highest melting point of any element. It readily forms hard, stable carbides in alloys, and for this reason most of the world production of the element (about 80%) is used in steel alloys, including high-strength alloys and superalloys. Most molybdenum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oliver E
Oliver may refer to: Arts, entertainment and literature Books * ''Oliver the Western Engine'', volume 24 in ''The Railway Series'' by Rev. W. Awdry * ''Oliver Twist'', a novel by Charles Dickens Fictional characters * Ariadne Oliver, in the novels of Agatha Christie * Oliver (Disney character) * Oliver Fish, a gay police officer on the American soap opera ''One Life to Live'' * Oliver Hampton, in the American television series ''How to Get Away with Murder'' * Oliver Jones (''The Bold and the Beautiful''), on the American soap opera ''The Bold and the Beautiful'' * Oliver Lightload, in the movie ''Cars'' * Oliver Oken, from ''Hannah Montana'' * Oliver (paladin), a paladin featured in the Matter of France * Oliver Queen, DC Comic book hero also known as the Green Arrow * Oliver (Thomas and Friends character), a locomotive in the Thomas and Friends franchise * Oliver Trask, a controversial minor character from the first season of ''The O.C.'' * Oliver Twist ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Robert Schrieffer
John Robert Schrieffer (; May 31, 1931 – July 27, 2019) was an American physicist who, with John Bardeen and Leon Cooper, was a recipient of the 1972 Nobel Prize in Physics for developing the BCS theory, the first successful quantum theory of superconductivity. Life and career Schrieffer was born in Oak Park, Illinois, the son of Louise (Anderson) and John Henry Schrieffer. His family moved in 1940 to Manhasset, New York, and then in 1947 to Eustis, Florida, where his father, a former pharmaceutical salesman, began a career in the citrus industry. In his Florida days, Schrieffer enjoyed playing with homemade rockets and ham radio, a hobby that sparked an interest in electrical engineering. After graduating from Eustis High School in 1949, Schrieffer was admitted to the Massachusetts Institute of Technology, where for two years he majored in electrical engineering before switching to physics in his junior year. He completed a bachelor's thesis on multiplets in heavy at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leon Cooper
Leon N. Cooper (né Kupchik; February 28, 1930 – October 23, 2024) was an American theoretical physicist and neuroscientist. He won the Nobel Prize in Physics for his work on superconductivity. Cooper developed the concept of Cooper pairs and collaborated with John Bardeen and John Robert Schrieffer to develop the BCS theory of conventional superconductivity. In neuroscience, Cooper co-developed the BCM theory of synaptic plasticity. Biography Childhood and education Leon N. Kupchick was born in the Bronx, New York City on February 28, 1930. His middle initial N. does not stand for anything, though some sources erroneously suggested his middle name was Neil. His father Irving Kupchik was from Belarus and moved to the United States after the Russian Revolution in 1917. His mother Anna (née Zola) Kupchik was from Poland; she died when Leon was seven. His father later changed the family's surname from Kupchick to Cooper when he remarried. Leon attended the Bronx High S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Bardeen
John Bardeen (; May 23, 1908 – January 30, 1991) was an American solid-state physicist. He is the only person to be awarded the Nobel Prize in Physics twice: first in 1956 with William Shockley and Walter Houser Brattain for their invention of the transistor; and again in 1972 with Leon Cooper and John Robert Schrieffer for their fundamental theory of superconductivity, known as the BCS theory. Born and raised in Wisconsin, Bardeen received a Ph.D. in physics from Princeton University. After serving in World War II, he was a researcher at Bell Labs and a professor at the University of Illinois. The transistor revolutionized the electronics industry, making possible the development of almost every modern electronic device, from telephones to computers, and ushering in the Information Age. Bardeen's developments in superconductivity—for which he was awarded his second Nobel Prize—are used in nuclear magnetic resonance spectroscopy (NMR), medical magnetic resonance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BCS Theory
In physics, the Bardeen–Cooper–Schrieffer (BCS) theory (named after John Bardeen, Leon Cooper, and John Robert Schrieffer) is the first microscopic theory of superconductivity since Heike Kamerlingh Onnes's 1911 discovery. The theory describes superconductivity as a microscopic effect caused by a condensation of Cooper pairs. The theory is also used in nuclear physics to describe the pairing interaction between nucleons in an atomic nucleus. It was proposed by Bardeen, Cooper, and Schrieffer in 1957; they received the Nobel Prize in Physics for this theory in 1972. History Rapid progress in the understanding of superconductivity gained momentum in the mid-1950s. It began with the 1948 paper, "On the Problem of the Molecular Theory of Superconductivity", where Fritz London proposed that the phenomenological London equations may be consequences of the coherence of a quantum state. In 1953, Brian Pippard, motivated by penetration experiments, proposed that this would mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
