Galvano-magnetic effects in bismuth alloys

Abstract

There are few phenomena of comparable importance to which so much attention has been devoted as to galvano-magnetic effects in bismuth, and few also where the results are so discordant. A bibliography of the earlier work can be found in Campbell’s book on the subject (1923), but in the light of present knowledge most of it is seen to be of little value, since the experiments were performed with polycrystalline material—and bismuth is above all things anisotropic. References are given at the end of this article to those papers which deal with single crystals, but even these are not much use, since the metal used was, by modern standards, anything but pure, and the impurities not known. Exceptions to this are the more recent papers by Kapitza (1928), Schubnikov and de Haas (1930), and de Haas, Gerritsen and Capel (1936), but each one of these covers only a limited range either of temperature or of magnetic field. In short, it is seen that no complete set of data exists for pure bismuth over an extended range of fields and temperatures, and that the effects of impurities present in the bismuth are only known in a vaguely qualitative way; for example, the various workers give values for the magneto-resistance coefficient of bismuth which, for the same values of field strength and temperature, differ by as much as a factor of twenty times.