Internal Lorentz force paradox

[pengkuan]

That's the whole point of it.

 

If both holes and real electrons apparently move in the same direction, what drives the electrons that move in the opposite direction to vacate the hole sites?

 

 

If I understand the problem, the question is: while the charge carriers are electrons in N type semiconductor, the stream of electrons are deflected upward in presence of magnetic field; why the holes in P type semiconductor are also deflected upward? Logically, holes are positive charges and must go downward.

 

I think that in P type semiconductor, the current is also a stream of electrons, because only electrons can move, holes are fixed charges in crystals. When the electrons flow, the hole they left are where they were before moving. As streams of electrons are deflected upward, the holes they leave are where the electrons move, that is, on the up side. So, the holes seem to be deflected upward too.

 

In fact, it is not the holes that are pushed up, but the moving electrons. On the down side, electrons are not moving and all holes are filled.

[studiot]

Hello pengkuan,

Thank you for your thoughts, but you are still not appreciating the significance of what I am saying or correctly interpreting the influence of electric and magnetic forces on current flowing in conductors and semiconductors.

 

Your diagrams are certainly ingenious, but there is a flaw.

 

If, as you propose, the movement of the holes is because the electrons 'take the holes with them' this would imply that the direction of hole movement and electron movement is always the same in any current. We know this not to be the case and that, in fact, the normal movement of holes is in a direction opposite to that of the electron's movement.

 

It is, however, easy to prove using the Lorenz formula, that when we apply a suitable magnetic field to a current with holes flowing one way and electrons the other, they are both deflected in the same direction.

 

The charge carriers moving in the y direction are not in equilibrium - they are moving.

 

The charge carriers do not actually move in the x direction (that of the Lorenz force) because they remain in equilibrium - held in place by the Hall voltage that is generated in the x direction.

 

That, in itself, would be fine and dandy and the end of the story if all Hall voltages we of the same sign.

 

But they are not. For silver and gold they are stronly positive, for aluminium and indium they are negative.

[pengkuan]

Hello studiot.

 

Your are not treating semiconductors, but conductors. There is not hole at all. The effect you observe is probably due to magnetic susceptibility .

Silver is a diamagnetic material, that is, it creates a magnetic field contrary to external one. But Aluminium is paramagnetic, it creates a magnetic field paralelle to external one.

 

The susceptibility of silver is −2.6 10e-5, that of Aluminium is 2.2 10e-5. It is a small value, but inside the material, the distance between electrons and magnetic sources is nearly 0. The Lorentz force can be significant.

 

Since sliver creates a negative magnetic field, its Hall effect is positive. Aluminium creates a positive magnetic field, its Hall effect is negative. The difference of volatge intensity is due to conductivity. Sliver is a much better conductor than Aluminium , its voltage is stronger.

pengkuan

That, in itself, would be fine and dandy and the end of the story if all Hall voltages we of the same sign.

 

But they are not. For silver and gold they are stronly positive, for aluminium and indium they are negative.

[studiot]

I was trying to be helpful in pointing you at a situation where it is acknowledged that the Lorenz force/electron particle model breaks down, but you seem to want to be argumentative about it, rather than reasearch for yourself.

 

Yes silver may be diamagnetic but electrons are not. They don't care what sort of atom they are in and I am talking about a model that predicts the effect of a magnetic field on a travelling electron.

Further the electron's motion is perpendicular to the applied magnetic field. It has negligible motion in the direction of the field that is the whole point of the Hall voltage. The Hall voltage is electrostatic.

 

You are right in observing the only numeric data I have to hand is for conductors, but the Hall effect also appears in semiconductors with some equally anomalous results.

[pengkuan]

Thank you for your kind indication. I will keep it for future.

 

I was explaining you the effect that seemed to puzzle you, not arguing about it.

 

For semiconductor, I'm sure that holes do not feel Lorentz force. I can explain you the mechanism if you want.

I was trying to be helpful in pointing you at a situation where it is acknowledged that the Lorenz force/electron particle model breaks down, but you seem to want to be argumentative about it, rather than reasearch for yourself.

 

[pengkuan]

Displacement magnetism experiment design

31 July 2012

 

 

According to Ampere-Maxwell equation, displacement current creates magnetic field. I call this theory displacement magnetism. I have proven that displacement magnetism violates energy conservation law and as a consequence, the wave equation is inconsistent (1,2,3).

 

The above conclusions need experimental test. I propose an experiment whose design is shown in the Figure 1. A round plate capacitor is charged by an alternate current, Ic. In the circuit a long rectangular loop is connected in series. The magnetic field variation in the space between the plates and outside the capacitor is measure by an EMF sensor. Another EMF sensor measures the magnetic field near the long side of the loop.

 

Please read the following document

Displacement magnetism experiment design http://pengkuanem.blogspot.com/2012/07/displacement-magnetism-experiment-design.html

[pengkuan]

Deformation of EM wave signals

14 August 2012

 

Electromagnetic wave carries signals emitted by antenna into space. The EM field of a wave is mathematically defined by the EM wave equation whose monochromatic solution is the equation (1). A signal is a time varying EM field that can be expressed by Fourier series which is the sum of monochromatic wave functions, that is, a sum of equation (1) of different amplitudes and wave lengths.

 

We notice that the amplitude and phase of the equation (1) vary with distance and frequency, that is, monochromatic EM waves of different frequencies evolve differently in space. In consequence, the form of the Fourier series is distorted, the traveling signal is deformed. What is the extent of the deformation of EM signal in space?

 

 

 

Please read the following document

Deformation of EM wave signals

http://pengkuanem.bl...ve-signals.html

[pengkuan]

I have published a new article. From now on, I will publish my articles in in my Science Forums' blog. Please read here

http://blogs.science...s.net/pengkuan/