Popis: |
The anisotropic scattering of conduction electrons in potassium by dilute concentrations of rubidium or sodium impurities, is discussed in terms of two theoretical models. In one, the anisotropy derives from the lattice strain field surrounding a substitutional impurity, whilst in the other it arises from the variation in the character of the electron wavefunctions over the Fermi surface in potassium. Both effects contribute in approximately equal measure and the present results, in a simple metal, highlight the need for a unified theory, such as might be provided by a cluster type of calculation. |