First, the relationship between resistivity and material properties
1, metal material
The resistivity of metal materials is usually low, because electrons in metals are easy to migrate and have good conductivity.
2. Semiconductor materials
The resistivity of semiconductor materials can be several orders of magnitude higher than that of metals, because of its low concentration of carriers (such as electrons and holes) and limited mobility.
3. Dielectric materials
The resistivity of dielectric materials is very high because they lack free electrons for electron migration.
4. Temperature
The resistivity of many materials varies with temperature. For example, the resistivity of metals usually increases with the increase of temperature, while the resistivity of semiconductors decreases with the decrease of temperature.
5, impurities and defects
Impurities and defects in materials will affect the resistivity. For example, impurities can provide additional carriers and affect the resistivity of semiconductors.
6, field effect
Under strong electric field, the resistivity of materials may change. For example, field effects in semiconductors can lead to changes in resistivity.
7. Hall effect
In the magnetic field, the resistivity of materials will change due to the Hall effect.
Second, the influence of temperature on conductor resistivity
1, with the increase of temperature, the number of carriers in the material increases, and these carriers will collide with the lattice during the movement, resulting in the increase of scattering and resistivity.
2. With the increase of temperature, the atomic vibration in the material will be intensified, which will also lead to the electron scattering and the increase of resistivity.
3. In a certain temperature range, the resistivity of some materials will change significantly with the change of temperature, which is called thermal effect.
4. At extremely low temperature, the resistivity of some materials will decrease with the decrease of temperature, and even superconductivity will occur.
5. At high temperature, the resistivity of some materials will change dramatically with the increase of temperature, which is called Seebeck effect.
Application of conductor resistivity
1, materials science research
By measuring the resistivity of different materials, the structure, phase transition and doping characteristics of materials are studied.
2, electronic device manufacturing
By measuring the resistivity of semiconductor, its conductivity and doping degree are determined, which is used to manufacture electronic devices.
3. Industrial production
By measuring the resistivity of metal materials, its conductivity and processing quality are evaluated.
4. Sensor application
By measuring the change of resistivity, it can be used to measure physical quantities such as temperature, pressure and humidity.