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YBCO
Yttrium barium copper oxide (YBCO) is a family of crystalline chemical compounds that display high-temperature superconductivity; it includes the first material ever discovered to become superconductivity, superconducting above the boiling point of liquid nitrogen [] at about . Many YBCO compounds have the general formula (also known as Y123), although materials with other Y:Ba:Cu ratios exist, such as (Y124) or (Y247). At present, there is no singularly recognised theory for high-temperature superconductivity. It is part of the more general group of rare-earth barium copper oxides (ReBCO) in which, instead of yttrium, other rare earths are present. History In April 1986, Georg Bednorz and Karl Alexander Müller, Karl Müller, working at IBM Research – Zurich, IBM in Zurich, discovered that certain semiconducting oxides became superconducting at relatively high temperature, in particular, a lanthanum barium copper oxide becomes superconducting at 35 K. This oxide was an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-temperature Superconductivity
High-temperature superconductivity (high-c or HTS) is superconductivity in materials with a critical temperature (the temperature below which the material behaves as a superconductor) above , the boiling point of liquid nitrogen. They are "high-temperature" only relative to previously known superconductors, which function only closer to absolute zero. The first high-temperature superconductor was discovered in 1986 by IBM researchers Georg Bednorz and K. Alex Müller. Although the critical temperature is around , this material was modified by Ching-Wu Chu to make the first high-temperature superconductor with critical temperature . Bednorz and Müller were awarded the Nobel Prize in Physics in 1987 "for their important break-through in the discovery of superconductivity in ceramic materials". Most high-c materials are type-II superconductors. The major advantage of high-temperature superconductors is that they can be cooled using liquid nitrogen, in contrast to previously known s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rare-earth Barium Copper Oxide
Rare-earth barium copper oxide (ReBCO) is a family of chemical compounds known for exhibiting high-temperature superconductivity (HTS). ReBCO superconductors have the potential to sustain stronger magnetic fields than other superconductor materials. Due to their high critical temperature and critical magnetic field, this class of materials are proposed for use in technical applications where conventional low-temperature superconductors do not suffice. This includes magnetic confinement fusion reactors such as the ARC reactor, allowing a more compact and potentially more economical construction, and superconducting magnets to use in future particle accelerators to come after the Large Hadron Collider, which utilizes low-temperature superconductors. Materials Any rare-earth element can be used in a ReBCO; popular choices include yttrium (YBCO), lanthanum ( LBCO), samarium (Sm123), neodymium (Nd123 and Nd422), gadolinium (Gd123) and europium (Eu123), where the numbers among paren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yttrium
Yttrium is a chemical element; it has Symbol (chemistry), symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and has often been classified as a "rare-earth element". Yttrium is almost always found in combination with lanthanide elements in rare-earth minerals and is never found in nature as a free element. 89Y is the only stable isotope and the only isotope found in the Crust (geology), Earth's crust. The most important present-day use of yttrium is as a component of phosphors, especially those used in LEDs. Historically, it was once widely used in the red phosphors in television set cathode ray tube displays. Yttrium is also used in the production of electrodes, electrolytes, electronic filters, lasers, superconductors, various medical applications, and Trace element, tracing various materials to enhance their properties. Yttrium has no known Biology, biological role. Exposure to yttrium compounds can cause Respiratory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superconductivity
Superconductivity is a set of physical properties observed in superconductors: materials where Electrical resistance and conductance, electrical resistance vanishes and Magnetic field, magnetic fields are expelled from the material. Unlike an ordinary metallic Electrical conductor, conductor, whose resistance decreases gradually as its temperature is lowered, even down to near absolute zero, a superconductor has a characteristic Phase transition, critical temperature below which the resistance drops abruptly to zero. An electric current through a loop of superconducting wire can persist indefinitely with no power source. The superconductivity phenomenon was discovered in 1911 by Dutch physicist Heike Kamerlingh Onnes. Like ferromagnetism and Atomic spectral line, atomic spectral lines, superconductivity is a phenomenon which can only be explained by quantum mechanics. It is characterized by the Meissner effect, the complete cancellation of the magnetic field in the interior of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barium
Barium is a chemical element; it has symbol Ba and atomic number 56. It is the fifth element in group 2 and is a soft, silvery alkaline earth metal. Because of its high chemical reactivity, barium is never found in nature as a free element. The most common minerals of barium are barite ( barium sulfate, BaSO4) and witherite ( barium carbonate, BaCO3). The name ''barium'' originates from the alchemical derivative "baryta", from Greek (), meaning 'heavy'. ''Baric'' is the adjectival form of barium. Barium was identified as a new element in 1772, but not reduced to a metal until 1808 with the advent of electrolysis. Barium has few industrial applications. Historically, it was used as a getter for vacuum tubes and in oxide form as the emissive coating on indirectly heated cathodes. It is a component of YBCO (high-temperature superconductors) and electroceramics, and is added to steel and cast iron to reduce the size of carbon grains within the microstructure. Barium compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paul Ching Wu Chu
Paul Ching Wu Chu (; born December 2, 1941) is a Taiwanese-American physicist specializing in superconductivity, magnetism, and dielectrics. He is a professor of physics and T.L.L. Temple Chair of Science in the Physics Department at the University of Houston College of Natural Sciences and Mathematics. He was the president of the Hong Kong University of Science and Technology from 2001 to 2009. In 1987, he was one of the first scientists to demonstrate high-temperature superconductivity. Early life and education Chu was born in Changsha, Hunan, Republic of China in 1941. Chu's family was from Taishan, Guangdong. Chu spent his childhood in Taiwan. In 1958, Chu graduated from Taiwan Provincial Cingshuei high school. In 1962, Chu earned his Bachelor of Science degree from National Cheng Kung University in Taiwan. In 1965, he earned his Master of Science degree from Fordham University. In 1968, he earned his Ph.D. degree from the University of California, San Diego. Career ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perovskite (structure)
A perovskite is a crystalline material of formula ABX3 with a crystal structure similar to that of the mineral perovskite, this latter consisting of calcium titanium oxide (CaTiO3). The mineral was first discovered in the Ural mountains of Russia by Gustav Rose in 1839 and named after Russian mineralogist L. A. Perovski (1792–1856). In addition to being one of the most abundant structural families, perovskites have wide-ranging properties and applications. Structure Perovskite structures are adopted by many compounds that have the chemical formula ABX3. 'A' and 'B' are positively charged ions (i.e. cations), often of very different sizes, and X is a negatively charged ion (an anion, frequently oxide) that bonds to both cations. The 'A' atoms are generally larger than the 'B' atoms. The ideal cubic structure has the B cation in 6-fold coordination, surrounded by an octahedron of anions, and the A cation in 12-fold cuboctahedral coordination. Additional perovskite for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georg Bednorz
Johannes Georg Bednorz (; born 16 May 1950) is a German physicist who, together with K. Alex Müller, discovered high-temperature superconductivity in ceramics, for which they shared the 1987 Nobel Prize in Physics. Life and work Bednorz was born in Neuenkirchen, North Rhine-Westphalia, Germany to elementary-school teacher Anton and piano teacher Elisabeth Bednorz, as the youngest of four children. His parents were both from Silesia in Central Europe, but were forced to move westwards in turbulences of World War II. including the Nobel Lecture, December 8, 1987 ''Perovskite-Type Oxides – The New Approach to High-Tc Superconductivity'' As a child, his parents tried to get him interested in classical music, but he was more practically inclined, preferring to work on motorcycles and cars. (Although as a teenager he did eventually learn to play the violin and trumpet.) In high school he developed an interest in the natural sciences, focusing on chemistry, which he could learn in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bell Laboratories
Nokia Bell Labs, commonly referred to as ''Bell Labs'', is an American industrial research and development company owned by Finnish technology company Nokia. With headquarters located in Murray Hill, New Jersey, the company operates several laboratories in the United States and around the world. As a former subsidiary of the American Telephone and Telegraph Company (AT&T), Bell Labs and its researchers have been credited with the development of radio astronomy, the transistor, the laser, the photovoltaic cell, the charge-coupled device (CCD), information theory, the Unix operating system, and the programming languages B, C, C++, S, SNOBOL, AWK, AMPL, and others, throughout the 20th century. Eleven Nobel Prizes and five Turing Awards have been awarded for work completed at Bell Laboratories. Bell Labs had its origin in the complex corporate organization of the Bell System telephone conglomerate. The laboratory began operating in the late 19th century as the Wester ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liquid Helium
Liquid helium is a physical state of helium at very low temperatures at standard atmospheric pressures. Liquid helium may show superfluidity. At standard pressure, the chemical element helium exists in a liquid form only at the extremely low temperature of . Its boiling point and critical point depend on the isotope of helium present: the common isotope helium-4 or the rare isotope helium-3. These are the only two stable isotopes of helium. See the table below for the values of these physical quantities. The density of liquid helium-4 at its boiling point and a pressure of one atmosphere (101.3 kilopascals) is about , or about one-eighth the density of liquid water. Liquefaction Helium was first liquefied on July 10, 1908, by the Dutch physicist Heike Kamerlingh Onnes at the University of Leiden in the Netherlands. At that time, helium-3 was unknown because the mass spectrometer had not yet been invented. In more recent decades, liquid helium has been used as a cryogenic refriger ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
