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从电子理论研究超导性已取得重要进展,但是还没有越出定性理论范畴,特别是对氧化物类超导性更是这样,超导性电子理论在作定量描述时产生了麻烦,因而超导材料的选择不得不借助于经验试验方法。本研究也是如此,在周期表元素中选取了所有电子结构区元素包括s区、d区、sp区、d~(10)s区等,在各区中分别各取一元素用之形成化合物,其目的是希望在多种花样的电子构型元素上,用之形成固体,这样有可能组成低密度的低位能级——相当于超导状态能级。另一方面取用这些元素时也考虑到它们能互相化合并且有适当阴阳离子半径比率的最重的元素,以期形成低熵状态,从这些原则出发可能较理想的氧化物超导材料体系是:Ba—Cd—La—O,Ba—La—Cu—O,Y—Ba—Cu—O等。本文对后两种体系进行了初步研究。采用CO_2激光加热这些金属元素的碳酸盐,由于碳酸根离子的v_2振动频率与激光频率较良好的匹配而容易吸收激光能量,并使碳酸盐体系发生分解为氧化物和二氧化碳,后者
Superconductivity has made significant progress from the electronic theory, but it has not yet gone beyond qualitative theory, especially for oxide superconductivity. The theory of superconductivity is troublesome for quantitative description, The choice of guide material has to resort to empirical test methods. The same is true in this study. All the elements of the electronic structure region, including s, d, sp, d ~ (10) s, were selected from the periodic table elements. The aim is to form a solid over a variety of triceps electronic configuration elements, which makes it possible to compose a lower density energy level - equivalent to the superconducting state energy level. On the other hand, taking these elements into account also takes into account the fact that they can be combined with one another and have the heaviest element with the appropriate ratio of anions and anions in order to form an under-entropy state. From these principles it may be desirable that the oxide superconducting material system be: Ba-Cd-La-O, Ba-La-Cu-O, Y-Ba-Cu-O and the like. This article has carried on the preliminary research to the latter two systems. The use of CO_2 laser to heat these metallic carbonates easily absorbs the laser energy due to the v_2 vibrational frequency of the carbonate ions matching the laser frequency and decomposes the carbonate system into oxide and carbon dioxide.