The study of the specific resistance of bismuth crystals and its change in strong magnetic fields and some allied problems
It is well known that in a magnetic field bismuth shows a greater change of resistance than any other substance, and it is also known that in the case of a crystal this phenomenon varies very much with the orientation of the crystal. A great deal of literature exists on this subject. The general view of the phenomenon is that the increase of resistance is largest when the cleavage plane of the crystal is parallel to the magnetic field, and when the current is flowing perpendicular to it. It is also known that the resistance in a magnetic field increases very rapidly with decreasing temperature. A complication in all these phenomena arises through certain time lags. When a current is passed through bismuth placed in a magnetic field, the resistance at the first moment is large, and then gradually decreases to its final value. This time lag accounts for the fact, first discovered by Lenard, that bismuth has a larger resistance for alternating currents than for direct currents. This phenomenon also depends on the crystal state of the bismuth.