STRONG MAGNETIC SCATTERING IN WEAK-LOCALIZATION

Theoretical analysis of weak localization for the three dimensional sy stem presently does not include the case with strong scattering by loc al magnetic impurities. For paramagnetic Fe0.33Zr0.67 alloy, a composi tion just below the ferromagnetic phase boundary, the magnetic impurit y scattering time (tau(s)) is estimated to be comparable to the spin-o rbit scattering time (tau(so)), but much less than the magnetic field dephasing time (tau(H)) or inelastic scattering time (tau(i)), so that the magnetic scattering occurs before the magnetic field dephasing do es. When the local moments of magnetic impurities (in this case some o f the Fe ions) do not interact with each other and their magnetization follows the Brillouin function, the magneto-resistance MR is proporti onal to n(s)(1/2)(H/T)(2) for small (H/T), where Ns is the density of local impurities of moment gS mu(B), and Delta rho(H, T)/rho(2) should be a unique function of (H/T), for a given alloy so long as the impur ities are in the Curie regime. Experimental values of the MR at severa l temperatures for the Fe0.33Zr0.67 alloy lie on a single curve of Del ta rho(H, T)/rho(2) vs. H/T.