Free Electron Model

In solid-state physics, the free electron model is a simple model for the behaviour of valence electrons in a crystal structure of a metallic solid. It was developed principally by Arnold Sommerfeld who combined the classical Drude model with quantum mechanical Fermi-Dirac statistics and hence it is also known as the Drude–Sommerfeld model. The free electron Empty Lattice Approximation forms the basis of the band structure model known as nearly free electron model. Given its simplicity, it is surprisingly successful in explaining many experimental phenomena, especially

• the Wiedemann-Franz law which relates electrical conductivity and thermal conductivity;
• the temperature dependence of the heat capacity;
• the shape of the electronic density of states;
• the range of binding energy values;
• electrical conductivities;
• thermal electron emission and field electron emission from bulk metals.