Resistance Minimum in Magnesium: Magnetoresistance

The magnetoresistance of two specimens of magnesium has been measured at liquid helium temperatures in transverse magnetic fields up to 25 kilogauss. One specimen, containing 0.013% iron as the predominant impurity and previously shown to possess a minimum in the electrical resistivity at 4.5°K, demonstrated a magnetoresistance which followed Kohler's rule quite exactly. The second specimen, containing 0.043% manganese and previously shown to have a rather large negative $\frac{\mathrm{dR}}{\mathrm{dT}}$ at helium temperatures, showed a small departure from Kohler's rule. The magnetoresistance observed in these specimens is in fair agreement with the majority of results previously reported by Thomas and Mendoza and by Yntema.