Thermoelectric Effect

In solid-state physics, an important topic of note is the thermoelectric effect, of which there is actually more than one. All of these effects, however, involve temperature changes and electricity.

Identification

• The thermoelectric effect occurs when there are two different metals, joined at both ends, to create a closed circuit. When one end has a different temperature applied to it than the other, a small current is created, which increases along with the variation in temperatures. This creates a thermocouple.

Types

• There are three major thermoelectric effects. The Seebeck effect describes the voltage created based on the temperature difference. The Peltier effect is the opposite and describes the temperature change created in a thermocouple that has a voltage. The Thomson effect describes the relationship between temperature and voltage, but in a thermocouple made out of only one type of metal.

Features

• The two metals most often used in thermocouples to create thermoelectric effects are copper and constantan. Copper-iron circuits are also popular, but they generate a much lower voltage. Antimony and bismuth, on the other hand, can create some of the highest voltages but are less common.