Then expression (7) is written as:

[zihadhosenjm40]

let us agree that the magnetic field is directed strictly perpendicular to the particle velocity vector . That is, the angle α between the vectors and is equal to 900, and sin(900)=1 Then:

Under the action of the Lorentz force, the electrons are deflected toward the near side face of the plate (Fig. 5) and charge it negatively. On the opposite face, an uncompensated positive charge of the ions of the crystal lattice remains. As a result, a transverse electric field arises in the plate , directed from the far side face to the near one. Let us denote the intensity of the resulting electric field by . The force acting from the electric field on the charge is directed in the direction opposite to the direction of the Lorentz force (Fig. 5). The transverse potential difference Ux that arises as a result of this is called the Hall EMF.

where n is the number of current carriers per unit volume of the sample (current carrier concentration).

On the other hand, the modulus of the current portugal mobile database vector is defined as, where S is the cross-sectional area of ​​the plate perpendicular to the direction. Then:


Let us designate where Rх is the constant or Hall coefficient. (It is conventionally assumed that the sign of the Hall constant coincides with the sign of the charge of the current carriers. For electron semiconductors, the constant R is negative, for hole semiconductors it is positive, where p is the hole concentration).


(8)

Thus, the Hall EMF depends on the magnitude of the current flowing, the magnetic field induction, the width of the plate, and the concentration of charge carriers. The dependence on concentration indicates that in metals the Hall EMF is much smaller than in semiconductors, and therefore the use of the Hall effect began only with the use of semiconductors.