Written by Adeel Abbas
Electrical conductivity is a measure of a material’s ability to conduct electric current. It is an important property that affects the performance of a wide range of applications, including electrical wiring, electronic devices, and batteries.
In this blog post, we will explore the factors that affect the electrical conductivity of metals, including their atomic structure, temperature, and impurities.
I have also written an article on how to measure electrical conductivity that you might also be interested in.
Atomic Structure of Metals
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The electrical conductivity of a metal is largely determined by its atomic structure. Metals are composed of atoms that are held together by a sea of delocalized electrons, which are free to move throughout the metal and contribute to its electrical conductivity. The more delocalized electrons a metal has, the better it will conduct electricity.
For example, copper has a high number of delocalized electrons and is therefore an excellent conductor of electricity. Hence it is used as electrical conductors.
On the other hand, insulators, such as rubber and glass, have very few delocalized electrons and do not conduct electricity well.
Temperature
Temperature is another factor that can affect the electrical conductivity of a metal. As the temperature of a metal increases, the motion of its atoms and electrons also increases. This can lead to an increase in the number of delocalized electrons available to carry current, resulting in an increase in electrical conductivity.
However, the relationship between temperature and electrical conductivity is not always linear. Some metals, such as copper and silver, have a relatively constant electrical conductivity over a wide range of temperatures. Others, such as aluminum and iron, have a more complex relationship with temperature and may exhibit a decrease in electrical conductivity at higher temperatures.
Impurities
Impurities, or foreign atoms, can also affect the electrical conductivity of a metal. When an impurity is introduced into a metal, it can disrupt the flow of delocalized electrons and reduce the metal’s ability to conduct electricity.
For example, pure gold is an excellent conductor of electricity, but the addition of small amounts of impurities, such as copper or silver, can significantly decrease its electrical conductivity. Similarly, the addition of impurities to copper can also reduce its electrical conductivity.
Doping
Doping is the process of introducing impurities into a material to alter its electrical properties. For example, silicon can be doped with impurities such as boron or phosphorus to create semiconductors, which have intermediate electrical conductivity compared to metals and insulators.
Strain
The electrical conductivity of a metal can also be affected by mechanical strain, or the stretching or compressing of the metal’s lattice structure. Strain can alter the distribution of delocalized electrons and affect the metal’s ability to conduct electricity.
Pressure
The electrical conductivity of a metal can also be affected by pressure, as the increased density of the metal can lead to an increase in the number of delocalized electrons.
In summary, the electrical conductivity of a metal is influenced by its atomic structure, temperature, and impurities, as well as other factors such as doping, strain, and pressure. Understanding these factors is important for optimizing the performance of a wide range of applications that rely on the electrical conductivity of metals.