Studies of exchange interactions in A-15 superconductors

Studies of conduction electron spin resonance have been made on various A-15 superconductors, namely, Nb
3
Ge,Nb
3
Sn,Nb
3
Si and V
3
Si in normal and superconducting states. The behaviour of CESR and spin waves under ditterent conditions strongly suggests that exchange interactions are present in the conduction band and the superconducting state is manifested by an order magnetic state. The conclusion is discussed in the light of the reported data of other workers.