Hall effect and the magnetic properties of some ferromagnetic materials

The Hall effect and the magnetic properties have been measured simultaneously with considerable accuracy in K.S. magnet steel and in hardened high carbon steel. The Hall effect is found to be a single-valued straight-line function of the intensity of magnetization I, but is neither a single-valued nor a straight-line function of either the magnetic induction B or the magnetic field H. This is true on both the virgin curves and the broad hysteresis loops of these materials. The possibility of writing the Hall e.m.f. per unit current in a cm square as ε=R0H+R1I is considered. In the materials measured here R0 is less than 0.005 R1. The formula may hold for non-ferromagnetic materials, but it could not be tested so simply.