Thermally Activated Deformation of Potassium

The thermally activated deformation of single crystal and polycrystalline potassium is examined. It is shown that the activation parameters describing low‐temperature deformation can be correlated reasonably well with the b.c.c. transition metals on the basis of their respective shear moduli. This supports the suggestion that the same general mechanism controls low‐temperature deformation for all b.c.c. materials. The possibility of this mechanism being either impurity or lattice controlled is examined and it is shown that the Peierls‐Nabarro lattice resistance model adequately explains the experimental behavior. The possible role of impurities at low temperatures is briefly considered.