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自从1911年荷兰科学家昂尼斯(H.K.Onnes)发现超导体,到1986年米勒(K.A.Muler)和贝德诺茨(J.G.Bednorz)研制成功超导转变温度为35K的氧化物超导体,整整走过75年艰难曲折的路程,进入了其发展的新阶段,这个阶段的特点是高温超导体研究及其应用,并走向产业化。 超导体的发现 昂尼斯于1911年在液氦温度下对水银的电阻进行测量时,发现在4.2K(液氦的正常沸点温)时水银的电阻在百分之几度的温度范围内骤然降到—个很小的数值,以至于是当时难以准确测量的数值(10~(-5)欧姆)。当他在水银中掺入大量杂质后,对其在液氦温度下向极小电阻状态转变并没有发生什么影响。这表明在低温下某些固体电阻趋于零是这些固体固有的物理性质。昂尼斯于1913年首次称这种状态为超导态。 新途径带来重大突破 沿着金属及其化合物的路径走了几十年,但始终未能得到高临界温度超导体。贝德诺茨和米勒另辟途径,转向对金属氧化物进行研究。1986年4月研制成功钡—镧—铜(Ba—La—Cu)系氧化物,实验观测到超导转变温度Tc为35K。这
Since the discovery of superconductors by the Dutch scientist HKOnnes in 1911, oxide superconductors with a superconducting transition temperature of 35 K developed by KAMuler and JGBednorz in 1986 have passed 75 years Difficult and tortuous journey, has entered a new stage of its development, this stage is characterized by high temperature superconductor research and its application, and to industrialization. Superconductor Discovery When Arnius measured the resistance of mercury at liquid helium temperature in 1911, it was found that at 4.2 K (the normal boiling temperature of liquid helium) the resistance of mercury drops suddenly to within a few tenths of a degree - a small value, so that it was difficult to accurately measure the value of the time (10 ~ (-5) ohms). When he mixed a lot of impurities in mercury, it had little effect on its transition to a very low resistance state at the liquid helium temperature. This shows that some solid resistance tends to zero at low temperatures are inherent physical properties of these solids. For the first time in 1913, Annecy called this state superconductivity. Breakthroughs with the new approach have gone decades along the path of the metals and their compounds, but have never been able to get high-temperature superconductors. Beide Knots and Miller, another way, turned to metal oxide research. In 1986 April successfully developed barium - lanthanum - copper (Ba-La-Cu) oxide, the experimental observation of the superconducting transition temperature Tc is 35K. This