thermomagnetic effects. Encyclopedia of radio electronics and electrical engineering
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Ettingshausen effect
It was discovered by the Austrian physicist A. Ettingshausen in 1886. Its essence lies in the appearance in a solid conductor, through which a current with a density J is passed and which is affected by a magnetic field with a strength H (perpendicular to the direction of the current), a temperature gradient ∆T / ∆x, which acts in a direction perpendicular to both the direction of the current and the direction of the magnetic field:
∆Т/∆x = Рµ0HJ,
where P is the Ettingshausen coefficient, µ0 is the initial magnetic permeability of the metal.
Rigi-Leduc effect
It was discovered in 1887 by the Italian physicist A.Righi and the French physicist S.Ledyuk. In a solid conductor, in which a temperature gradient ∆T / ∆x is created in a certain direction and a magnetic field with strength H is applied perpendicular to it, a secondary temperature gradient ∆T / ∆y arises in the direction perpendicular to and ∆T / ∆x and the direction of the magnetic field:
∆Т/∆y = Sµ0H(∆Т/∆x),
where S is the Righi-Leduc coefficient, µ0 is the initial magnetic permeability of the metal.
Nernst-Ettingshausen effect
It was discovered in 1886 by the German physicist W. Nernst and the Austrian physicist A. Ettingshausen. In a solid conductor, in which a temperature gradient ∆T / ∆x is created in a certain direction and a magnetic field with strength H is applied perpendicular to it, an electric voltage E appears in two directions - parallel to the temperature gradient and perpendicular to the temperature gradient (but in both cases perpendicular to the magnetic field ):
E = Qµ0H(∆Т/∆x),
where Q is the Nernst-Ettingshausen coefficient.
The coefficients P, S, Q are indicated in the table below for various metals.
See other articles Section Electricity for beginners.
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