G. A. Swallow

Magnetoresistance of a dilute PtFe alloy

The electrical resistivity of a Pt 0.05 at% Fe sample has been measured between 1.5 K and 10 K and in magnetic fields up to 60 kOe. The magnetoresistance is found to be negative, and is well described using an s-d model in which the s electrons scatter off the giant moments known to exist in this system. Values of the spin and g-factor for the giant moment are found, and the latter is compared with a theoretically predicted value.

Magnetization and magnetoresistance of the localized spin fluctuating system PtCo

The susceptibility, magnetization, resistivity and magnetoresistance of a Pt‐0.061 at.% Co sample have been measured between 1.5 and 15 K in applied magnetic fields varying up to 59 kOe. The susceptibility data have been fitted to two phenomenological expressions, both of which yield a characteristic temperature of a few degrees. The magnetization data are complex, but they can be understood qualitatively by using the idea of an effective temperature. Finally, except at the highest field an lowest temperature, the magnetoresistance data is well represented by the predictions of localised spin fluctuation (lsf) theory, from which an lsf temperature of 0.7±0.1 K is estimated for this system.