Hall field

Assuming that the current in the gas is carried mostly by electrons, the induced electric field uB causes transverse electron motion (electron drift), which, being itself orthogonal to the magnetic field, induces an axial electric field, known as the Hall field, and an axial body force, F, given by... 

Figure 7-33. ODMR spectra of pristine and C o-doped DOO-PPV. Inset hall-field signal of doped sample.

In a later section (18d) we will find that the mixed-conductivity terms in fact allow a and R to be magnetic field dependent even when is independent of energy. This is because the Hall field Ey can never exactly balance the magnetic field forces for both holes and electrons at the same time. 

It follows from the conditions (307) that the expression for the Hall field (E2) in case (a) is... 

For the two-carrier system, the situation is considerably different. In this case, referring to Fig. 3b, thermal energy is transported by both holes and electrons and the Ettingshausen effect is mainly due to generation of hole-electron pairs at one side of the sample and their recombination on the other side. In addition, if the number densities and the mobilities of the holes and electrons are equal, the Hall effect and thus the opposing Hall field vanishes. In this case, the Ettingshausen effect is expected to be quite large. 

Hence the Hall field varies linearly with the magnetic field H. Introducing the density of electron per unit volume of conductor, n in m it is possible to relate the velocity of the electrons to the current density in A.m along the x-axis as follows ... 

Hall field detected across electrodes HR Han mobility from m" F h A.c. 

Ey and pn denote the Hall field and the Hall resistivity (or the transverse resistivity), respectively. 

Fig. 6. The orientation of the current density J the Hall field Ey and the magnetic field H with respect to the geometry of the sample.

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