The change of electrical conductivity in strong magnetic fields. Part I. —Experimental results

Abstract

In a recent paper the author described experiments on the change of resistance of bismuth crystals in magnetic fields up to 300,000 gauss. In agreement with previous investigators it was found that the resistance of bismuth in weak fields increases in proportion to the square of the magnetic field, and in stronger fields follows a linear law, the increase of resistance being proportional to the magnetic field up to fields of 300 kilogauss. It was further found that this linear part of the change of resistance is, in most cases, independent of the orientation of the crystal in the magnetic field, and also of the degree of perfection of the crystal. This suggests that we are concerned with an atomic phenomenon. On studying several other substances it was found that the increase of resistance, although on a much smaller scale, is similar to that observed in bismuth, following first the square law and in fields above 60 to 100 kilogauss a linear law. This has led to a systematic study of the elements throughout the periodic table. About 35 different metals have been investigated at different temperatures, varying from room temperature to the temperature of liquid nitrogen, and the law of change of resistance mentioned above is found to be general for all.