功能材料雙語-電功能材料(參考版)
2025-01-15 15:39本頁面
【正文】 GaAs is therefore used only where silicon is not sufficient. binary solid solution： BiSb ternary solid solution： Hg1xCdxTe、 GeAs1xPx Infrared detector material（ 紅外探測材料 ） Highspeed response devices（ 高速響應器件 ） 、 photomunication （ 光通信 ） 3. solid solution Use of semiconductors ?A semiconductor diode(半導體二極管 ) (devices that allow current in only one direction) consists of ptype and ntype semiconductors placed in junction with one another. ?Currently, most semiconductor diodes use doped silicon or germanium. LED 。 ? it can be alloyed to ternary and quaternary positions, with adjustable band gap width, allowing light emission at chosen wavelengths, and allowing . matching to wavelengths with lowest losses in optical fibers。 ? wider band gap, which allows operation of power devices at higher temperatures, and gives lower thermal noise to low power devices at room temperature。 ? showing variable resistance(可變電阻 )。 or higher than the critical magic field Hc, critical current Jc ,the regions separateed by Tc、 Hc， Jc. Josephson effect（約瑟夫森效應） The Josephson effect is the phenomenon of supercurrent—. a current that flows indefinitely（ 無限期的 ） long without any voltage applied—across a device known as a Josephson junction (JJ), which consists of two superconductors coupled by a weak link. ? The weak link can consist of a thin insulating barrier (known as a superconductor–insulator–superconductor junction, or SIS), a short section of nonsuperconducting metal (SNS), or a physical constriction that weakens the superconductivity at the point of contact (SsS). development of superconductor 77 K ?By material: ? chemical elements ? alloys ? ceramics ? anic superconductors Applications ?Superconducting mags(超導磁體 ) are some of the most powerful electromags(電磁鐵 ) known. They are used in Magic Resonance Imaging(MRI， 磁共振成像 ) /nuclear magic resonance(NMR， 核磁共振成像 ) machines, mass spectrometers(質譜儀 ), and the beamsteering mags (光束轉向磁體 )used in particle accelerators(粒子加速器 ). 粒子加速器 內部溫度： 4萬億攝氏度 工作溫度是 ℃ ，比外太空還冷 ?In the 1950s and 1960s, superconductors were used to build experimental digital puters using cryotron switches（ 低溫開關 ） . More recently, superconductors have been used to make digital circuits based on rapid single flux quantum （ 快速單量子通量 ） technology and RF （ radio frequency， 無線電頻率 ） and microwave filters（ 微波過濾器 ） for mobile phone base stations. ?Superconductors are used to build Josephson junctions which are the building blocks of SQUIDs (superconducting quantum interference devices), the most sensitive magometers（ 磁力計 ） known. ?SQUIDs are used in scanning SQUID microscopes and m
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