Pulsed Magnetic Field Studies of the Negative Magnetoresistivities of Dilute Ti-Mn and Cu-Mn Alloys at Low Temperatures

Measurements of the low-temperature negative magnetoresistivities of dilute Ti-Mn and Cu-Mn alloys have been extended to higher magnetic fields by means of pulsed magnetic field techniques. At 4.2^∘{}K the observed decreases of resistivity in a transverse magnetic field of 130 kG are approximately 5, 23, and 26% of the zero-field resistivity, respectively, for Ti-0.101 at.% Mn, Ti-1.00 at.% Mn, and Cu-1.00 at.% Mn. Saturation of the negative magnetoresistivity is essentially complete in Ti-0.101 at.% Mn below 100 kG. A trend toward saturation is strongly evident in Ti-1.00 at.% Mn and is less marked in Cu-1.00 at.% Mn. Close agreement between transverse and longitudinal magnetic field measurements is observed in all cases. The Ti-Mn data are in accord with earlier evidence which suggests that in these alloys there exist localized magnetic states which interact with the conduction electrons.