Changes in the Work Function of Iron in the α⇌γ Transformation Region

The work function of a polycrystalline iron filament changes somewhat abruptly in the α⇄γ transformation region. This change has been calculated from both electron‐emission and positive‐ion‐emission experimental data. From the electron‐emission results the difference φγ − φα is about 0. 09 eV, while from the positive‐ion‐emission results this difference is about 0. 06 eV.