Читать книгу Flexible Thermoelectric Polymers and Systems - Группа авторов - Страница 21

The temperature dependence of the conductivity is related to the charge transport mechanism. Varying the temperature does not affect the charge carrier density but the charge carrier mobility of metals. As the lattice vibrations become stronger at higher temperature, the scattering of the conduction electrons by lattice vibrations becomes more significant at higher temperature. This lowers the charge carrier mobility. The conductivity of metals thus decreases with the increasing temperature. There are two empirical formulas for the temperature dependence of the resistance of metals. One is the power law form,

(1.15)

The resistivity (ρ) at temperature (T) is related to the resistivity (ρ ₀) at the reference temperature (T ₀). The resistivity linearly increases with temperature in another form, and the temperature effect is characterized by the temperature coefficient of resistivity (α ₀),

(1.16)

In both forms, the resistivity of metals increases with the increasing temperature.