Learn about the five most common types of thermoelectric effects, including Seebeck, Peltier, Thomson, Ettingshausen, and Nernst effects. Discover their applications, advantages, and limitations.

5 Most Common Types of Thermoelectric Effects

Thermoelectricity is the conversion of temperature difference into electric voltage or current. This process has been utilized in a variety of applications, including power generation, temperature measurement, and cooling. The thermoelectric effect is a phenomenon in which the temperature difference between two materials results in a voltage or current. There are five different types of thermoelectric effects that are commonly used in practical applications. In this article, we will discuss the five most common types of thermoelectric effects.

Seebeck Effect

The Seebeck effect is the most common type of thermoelectric effect, discovered by Thomas Johann Seebeck in 1821. This effect occurs when a temperature gradient is applied across a conductor, which causes a voltage to develop. The voltage is proportional to the temperature difference, which is described by the Seebeck coefficient. The Seebeck effect is commonly used in thermocouples for temperature measurement and in thermoelectric power generators.

Peltier Effect

The Peltier effect is the opposite of the Seebeck effect, discovered by Jean Charles Athanase Peltier in 1834. This effect occurs when a current is passed through a junction of two dissimilar materials, causing a temperature difference across the junction. The direction of the temperature difference is dependent on the direction of the current flow. The Peltier effect is commonly used in thermoelectric coolers and heat pumps.

Thomson Effect

The Thomson effect, discovered by William Thomson (Lord Kelvin) in 1851, is the phenomenon in which a temperature difference between two ends of a conductor causes a current to flow through the conductor. The direction of the current flow is dependent on the direction of the temperature gradient. The Thomson effect is commonly used in thermoelectric power generators.

Ettingshausen Effect

The Ettingshausen effect is similar to the Peltier effect but occurs in the presence of a magnetic field. It was discovered by Albert von Ettingshausen in 1851. This effect occurs when a current is passed through a junction of two dissimilar materials in the presence of a magnetic field, causing a temperature difference across the junction. The direction of the temperature difference is dependent on the direction of the current flow and the magnetic field. The Ettingshausen effect is used in magnetic refrigeration and thermomagnetic power generation.

Nernst Effect

The Nernst effect, discovered by Walther Nernst in 1886, is the phenomenon in which a magnetic field applied to a conductor with a temperature gradient induces a transverse voltage. The direction of the voltage is perpendicular to both the temperature gradient and the magnetic field. The Nernst effect is commonly used in the measurement of magnetic fields and in the study of materials with high magnetic susceptibility.

In conclusion, thermoelectric effects are a fundamental part of many modern technologies, from temperature measurement to cooling and power generation. The five most common types of thermoelectric effects are the Seebeck effect, Peltier effect, Thomson effect, Ettingshausen effect, and Nernst effect. Each effect has its own unique characteristics and is used in specific applications. Understanding the principles of thermoelectricity is important for developing new and more efficient thermoelectric devices.