What is "nernst effect"

In physics and chemistry, the Nernst Effect (also termed first Nernst–Ettingshausen effect, after Walther Nernst and Albert von Ettingshausen) is a thermoelectric (or thermomagnetic) phenomenon observed when a sample allowing electrical conduction is subjected to a magnetic field and a temperature gradient normal (perpendicular) to each other. An electric field will be induced normal to both.

This effect is quantified by the Nernst coefficient |N|, which is defined to be

where E is the y-component of the electric field that results from the magnetic field's z-component B and the temperature gradient dT/dx.

The reverse process is known as the Ettingshausen effect and also as the second Nernst-Ettingshausen effect.