LXXXVI. Electrical and thermal magneto-resistance in thin rods of pure sodium

Measurements are reported on the electrical and thermal resistivity of 130 μ and 350 μ diameter rods of high purity sodium in transverse magnetic fields (0 to 10 000 oersteds) and at temperatures between 2 and 18°K. These indicate that in the thinner specimen at liquid helium temperature the mean free path is limited by the dimensions of the specimen and that relatively small magnetic fields, of magnitude such that the radius of the electron orbit is comparable with that of the rod, decrease the resistance. At higher fields a linear increase in resistance with field is observed, the relative increase being less at higher temperatures where lattice vibration scattering of the electrons is predominant.