The theory of alloys in the γ-phase

Abstract Binary alloys in the γ-phase according to Endo and Bernal have especially large diamagnetic susceptibilities. It appears also that the Hall coefficients may be much greater for the alloys in this phase than for either of the constituent pure metals. It will be shown that it is possible to relate these properties to the crystal structure of the alloys, and to the fact that the composition within the γ-phase follows the Hume-Rothery electronic rule. For alloys in this phase the rule states that there are 21 loosely bound, or valency electrons, to every 13 atoms. A reason will also be shown to exist for this rather odd ratio of the number of approximately free electrons to the number of atoms. The remainder of this section gives a summary of results already known which we shall require.