Negative magnetoresistance in (SN)x single crystal

The magnetoresistance in (SN)x single crystals is composed of the normal positive and negative components. The former increases in proportion to the square of the magnetic field B². The latter is remarkable at temperatures below 4.2 K and saturates at relatively low magnetic field (? 30 kG). The coefficient $\text{S(=}\text{lim}\text{B→0}\text{{??}\text{(}\text{δρ}\text{ρ}{}_0\text{)}\text{?B}{}^2\text{})}$ of this negative magnetoresitance shows features similar to those of semiconductors with Toyozawa's theory. These results of negative magnetoresistance are explained in terms of carrier scattering by localized magnetic moments.