On the electron scattering and dephasing by the nuclear spins
  We show that scattering of the conduction electrons by nuclear spins via the hyperfine interaction may lead the upper limit on the mean free path in clean metals. Nuclear spins with s >1/2 may cause a strong dephasing in dirty limit due to the quadrupole coupling to the random potential fluctuations caused by static impurities and lattice imperfections. 
A.M. Dyugaev, I.D. Vagner and P. Wyder