The low temperature metallic superconductor, since its discovery in 1911, has followed the path of T_c rise at a rate of about one Kelvin every four years, reaching the max. 23K in 1973 with the material Nb_3Ge as shown in Fig. 1. Immediately after the discovery, it was hoped that superconductivity would be able to generate a high magnetic field with much less consumption of electricity, of which the trial turned out to be in a vain. The Meissner- Ochsenfeld effect explained why the superconductivity was destroyed under a strong magnetic field.
展开▼