Relationship Between Doping YBCO, MgB₂ And Rare-earth Iron Oxyarsenides Superconductivity With Topological Index

Since the discovery of superconductor, the research of superconductive material has potential economic value and widely applied areas because of its particular physical properties. Especially the discovery of high critical temperature copper-oxide superconductors set off the study of high critical temperature superconductor. When the emergence of high-temperature copper-oxide superconductors, the superconducting critical temperature go into the liquid nitrogen temperature region, and further scientists set off a wave of high-temperature superconductivity. Then find the transition temperature of MgB₂ superconductors 39K, since the material has been found, physics, chemistry and other disciplines has attracted wide attention The new iron-based oxyarsenides high temperature superconductor of LaOFeAs in February of 2008 has broadened the peoples' thinking. Up to now, its critical temperature has breakthrough 50k by doping the lanthanide or under pressure. But today, although the world for many laboratories and research groups have carried out three large amount of superconductor research, and achieved great results. However, a systematic study of three different superconductors is seldom. In this paper, the topological index of commonly used mathematical methods, comprehensive comparison of the three doping laws for the use of superconductors to provide the theoretical and experimental reference.Through research showed that: most of the doped MgB₂ system of the electronegativity topological index°F is in the range of 2.7660 3.4908.°F near the 2.9255 is better, regardless of°F is greater than (or less than) 2.9255, supercon- ducting transition temperature T_c is°F with the increase (or decrease) and reduced, and significant trends.For the doped iron arsenide superconductor matrix, valence electron average energy level topological index between 37.5 39.5 as the main concentration area, while the vast majority of the corresponding distribution of T_c values in the range of 20k 40k, when the average energy of valence electron energy Index near the 38 level topology, the doping ratio of the best, may get a higher transition temperature. Topological index increased from 38, the corresponding transition temperature, but reduced, while the three non-doped superconductivity without exception, are higher than 40 when on duty.Y series oxide superconducting valence electron orbital energy topological index°E value in the time between 13.9536 and 16.1452, Y series high-temperature superconducting oxides exhibit good superconductivity. When°E value of Bi series high-temperature oxide superconducting is in two intervals that are from 15.8045 to 16.3455 and from 19.5900 to 20.3772, it showed good superconductivity.