As temperature increases, the electrical resistivities of pure metals ...
Such as copper, silver, and gold) generally increase. This is due to the increased thermal vibrations of the metal atoms, which disrupt the flow of electrons and increase resistance to the flow of electric current. This phenomenon is known as "thermal resistivity" or "temperature coefficient of resistivity."
However, it is important to note that the relationship between temperature and resistivity is not linear for all metals. Some metals, such as tungsten and nichrome, exhibit a decrease in resistivity with increasing temperature. This is due to the contribution of electron-phonon scattering, which becomes dominant at higher temperatures.
In general, the resistivity of a pure metal can be described by the equation:
ρ(T) = ρ0 * (1 + α * (T - T0))
where ρ(T) is the resistivity at temperature T, ρ0 is the resistivity at a reference temperature T0, and α is the temperature coefficient of resistivity. The temperature coefficient of resistivity is a material-specific constant that quantifies the change in resistivity per unit change in temperature.
It is worth mentioning that the temperature coefficient of resistivity can vary significantly between different metals. For example, silver has a relatively low temperature coefficient of resistivity, making it a good conductor even at high temperatures. On the other hand, materials like tungsten and nichrome have higher temperature coefficients of resistivity, making them suitable for applications where resistance needs to be stable over a wide temperature range, such as in heating elements.