Shockley (Shockley), William( The American physicist, Nobel Prize in Physics, 1956)
Comments for Shockley (Shockley), William
Biography Shockley (Shockley), William
February 13, 1910, Mr.. - August 12, 1989
American physicist William Bradford Shockley was born in London, the son of William Hillman Shockley, a mining engineer, and Mae (nee Bradford) Shockley - Federal Inspector of Mines. When he was three years, the family returned to the United States and settled in Palo Alto (Calif.), where W. received primary education. His parents encouraged his interest in physics, under the influence of their new neighbor, taught physics at Stanford University.
After graduating in 1927. secondary school in Hollywood, W. entered the University of California at Los Angeles and a year later transferred to the California Institute of Technology, which ends in 1932. with a bachelor. The teachers' scholarship, he enrolled in graduate school at Massachusetts Institute of Technology (MIT) in 1936. defended his doctoral thesis on 'Calculation of the wave functions for electrons in crystals of sodium chloride' ( "Calculations of Wave Functions for Electrons in Sodium Chloride Crystals"). Solid State W. studying at MIT, and his work on the crystal becomes a solid foundation for further scientific work.
In 1936, Mr.. he becomes a member of the laboratory telephone company 'Bell' in Murray Hill (New Jersey), where he worked with Clinton J. Davisson. First task W. was projecting electron multiplier - a special kind of electron tubes, acting as an amplifier. He then engaged in research on solid state physics and in 1939. puts forward plan to develop solid state amplifiers as an alternative to vacuum tubes. His project was unfeasible because of lack of time necessary materials, . but the basic idea coincided with the general thrust of all activities of the laboratory 'Bell' - with the development of telephony on the basis of no mechanical switches, . and electronic devices.,
. During the Second World War Z
. working on military projects, first on the electronic equipment field radar station firms 'Bell'. From 1942 to 1944. acting Director of Science Research Group ASW operations, established by the Office of the Navy at Columbia University in New York, from 1944 to 1945. is a consultant with the Office of the Minister of War. New area, . known as 'operations research', . set itself a purely military tasks, . to analyze and solve scientific methods, . such as the development of optimal schemes of dropping depth charges in the hunt for submarines or the optimal time and for the purposes of bombers.,
. In 1945, Mr.
. SH. returned to the laboratory 'Bell' as a director of research programs in solid state physics. His group consists of a theoretical physicist John Bardeen and experimental physicist Walter Brattain. Group resumes begun before the war, the study of materials known as semiconductors. Semiconductors have electrical conductivity intermediate between good electrical conductors (which include most metals) and insulators. Electrical conductivity of semiconductors is highly variable depending on temperature, as well as the nature and concentration of impurities in the material. Semiconductors have been used as a rectifier - a device conducting electricity only in one direction and can therefore convert AC to DC. In the first radio signals as a rectifier of radio waves, the receiving antenna, used for contact between the 'cat mustache' (coil of wire) and crystals of galena (semiconducting minerals).
. Over time, the crystals were replaced vacuum tubes, which have become the most important and common electronic devices
. The emergence of amplifier tubes paved the way for the growth of the electronics industry, but the life of lamps was relatively short, for heating the cathodes needed supplementary energy consumption, fragile glass containers occupy a large amount of. SH. and his group hoped to overcome these shortcomings by making amplification from rectifying current semiconductors.
. Although the application of quantum theory to solid state physics and expanded knowledge of the properties of semiconductors, the theory has not been adequately confirmed by experiments
. SH. intended to simulate the basic principle of an electronic tube devices by applying an electric field across the semiconductor in order to control the passage of electric current. While calculating W. showed that such a field should lead to increased current, to get practical results have not been able to. Bardeen suggested that electrons are trapped in the surface layer, which prevents the penetration of the field inside the semiconductor. For this a good idea followed by a series of experiments to study the surface effects. These experiments have helped the three researchers understand the complex behavior of semiconductor devices.
It was known that the conductivity in semiconductors made of two types of carriers: electrons and 'holes'. Electrons participating in conduction - this excess electrons from those that bind the atoms and the solid crystal. The holes correspond to the missing electrons. Since an electron carries a negative charge, unfilled electronic state behaves like a positive charge of the same magnitude. The holes also have the ability to move, although not as fast as electrons, and in the opposite direction. When a neighboring electron moves 'forward' to fill the hole he leaves behind him a new hole, so it looks as if the hole is moving back. Group W. found that the contribution of hole current to total current is usually underestimated. Inputs to the pure crystal in the form of impurity atoms, violate a regular crystalline structure, create a domain with an excessive amount of electrons (n-type) or holes (p-type).
In 1947, Mr.. Bardeen and Walter Brattain achieved the first success by building a semiconductor amplifier or transistor (transfer from the English words plus a resistor, from the Latin. resisto - resist). The final instrument consisted of a block of germanium (n-type semiconductor) with two closely spaced point contacts ( 'cat's whiskers') on one face on the opposite face. By the same terminal (emitter) to make a small positive voltage on the wide electrode (base) and a large negative voltage on the second contact (the collector). Signal voltage supplied to the emitter with a constant offset, is transmitted with a significant increase in the collector circuit. At the heart of the transistor is the introduction of holes in germanium in contact-emitter and their movement to contact the collector, where the holes increase the collector current. Subsequent events unfolded rapidly W. proposed to replace the point contact Rectifying junctions between the p-and n-type in the same crystal. Such a device, called the planar transistor was manufactured in 1950, Mr.. It consisted of a thin p-region enclosed between two n-regions (all regions have separate external contacts). Junction transistor thoroughly pressed with point-contact transistor, . so as to produce a planar transistor was much easier, . and it operates reliably Improved methods of cultivation, . cleaning and processing of silicon crystals allowed a long-standing idea of W,
. the creation of the transistor-based field effect. Now this type of transistor most widely used in electronic devices. Modern industry is able to release tiny silicon crystals, . each of which can fit hundreds of thousands of transistors, . and this number continues to grow crystals stimulated the appearance of such rapid development of modern computers, . Laptop, . palm of a hand calculator, . sophisticated communications, . control devices, . hearing aids, . Medical probes and other electronic devices.,
. In 1956, Mr.
. S., Bardeen and Brattain were awarded the Nobel Prize in Physics 'for the study of semiconductors and the discovery of the transistor effect'. At the presentation ceremony E.G. Rudberg, a member of the Royal Swedish Academy of Sciences, described their achievement of 'a model of foresight, wit and perseverance in achieving the goal'.
W. remained from the laboratory 'Bell' to 1955, . in the last year was head of research in physics of transistors He also held various positions outside the laboratory - has been a visiting lecturer at Princeton University (1946), . Advisor on Science of the Political Committee of the Joint Commission on Research and Development (1947 ... 1949) and a member of the Scientific Advisory Committee of the U.S. Army (1951 ... 1963),
. In 1954 ... 1955. SH. was a visiting professor at Caltech and leader of research group evaluation of weapon systems the U.S. Defense Department from 1958 to 1962 he was also a member of the scientific advisory committee of the Air Force United States.,
. After retiring from the laboratory 'Bell' W
. creates Shockley semiconductor laboratory (later transistor Shockley corporation that is a member of the company, Beckman and instuents') in Palo Alto, engaged in the development of transistors and other semiconductor devices. In 1968. firm after a double shift owners ceased to exist.
In 1962. SH. was appointed a member of the Advisory Scientific Committee of the workforce under the President of the USA. He was also a member scientific advisory committee of the NASA (National Aeronautics and Space Administration). In 1963, Mr.. SH. was appointed the first Professor of Engineering and Applied Sciences at Stanford University, where he taught until retirement (1975).
Teaching at Stanford, stimulated by W. interest in the improvement of scientific thinking. His ideas for improving society in the end caused controversy among geneticists. U W. was convinced that mankind is threatened by a kind of 'deterioration of the rock', because people with lower IQ are born more children than people with a higher rate. His remarks that had carried the first general in nature, soon began to acquire more racist tinge. Thus, in 1970, speaking at the U.S. National Academy of Sciences, he stated that he conducted research 'inevitably lead to the conclusion that racial-genetic basis of the problems of the Negro population of America'. For these views he was strongly criticized by many public figures and scholars, stressing, however, that the scientific significance of the achievements of Z. can not be undermined by his judgments about genetics.
Also works on physics of semiconductors and transistors, W. made an important contribution to the use of the properties of magnetic materials for the memory banks of computers and the development of electromagnetic theory. The range of his interests included the energy bands in solids, the plastic properties of metals, theory of grain boundaries (surfaces, share the tiny crystals that form polycrystalline body), order and disorder in alloys. SH. received more than 90 patents for inventions.
In 1933. He married Jean Alberta Bailey. They had two sons and a daughter. In 1955, Mr.. They divorced, and in the same year, W. married a second time, for an Emmy Lenning, a nurse to care for mentally ill. In his younger years he was an avid mountain climber. According to his second wife, W. mountaineering is not treated as a form of rest, but as a problem that needed to solve, and thoroughly trained, preparing themselves for such a decision. In later years he preferred sailing, swimming and diving for pearls.
In addition to the Nobel Prize, W. the U.S. government awarded the Medal of Merit (1946), . awarded the Morris Liebmann Award of the Institute of Radio Engineers (1952), . Oliver Buckley Prize for Solid State Physics of the American Physical Society (1953), . Comstock Prize of the American National Academy of Sciences (1954), . Holley medal of the American Society of Mechanical Engineers (1963), . honorary medal of the Institute of Electrical and Electronics Engineers (1980),
. He was a member of the U.S. National Academy of Sciences, the American Physical Society, the American Academy of Arts and Sciences, the Institute of Electrical and Electronics Engineers.