Engineering Physics

5.6 Sources of electrical resistance

In a metallic crystal, the electrons move through periodically varying electric potentials (or fields) of positive ions of the lattice. The cause for electrical resistance is the electron scattering and the cause for electron scattering is the non-periodicity of the lattice potentials. The causes for non-periodicity of lattice potentials are: (i) impurities in crystals, (ii) crystal defects (or imperfections) and (iii) thermal vibrations.

Freely moving electrons are associated with de Broglie [or matter] waves. In a perfect crystal, an electron moves similar to an electromagnetic wave without attenuation so that the mean free paths of electrons will be of several hundred Angstroms. This is in agreement with ...