A15型超電導体のH_c2

抄録

A review is given on the current research subjects on the upper critical field H_c2 in A15 superconductors such as Nb₃Sn and V₃Ga. After the brief introduction of the physical mechanisms determining H_c2, the following topics are dealt with; (1) the correction to the Pauli spin paramagnetic effect due to many-body interactions, (2) the effects of the martensitic transformation and disorder onH_c2 in both single crystals and practical conductors, (3) the tertiary element effects and (4) problems remained in future.