Thermionic Emission Effects on Surfaces

In summary, continuous emission of electrons from a surface will result in a decrease in the number of electrons on that surface, leading to a positive charge. This process can continue until a certain point where the potential energy required to remove more electrons becomes too high. Therefore, it is not possible for all electrons to be completely removed from the surface. This can be observed in a gold leaf electrode experiment where exposure to ultraviolet radiation causes the leaf to spread out due to electron emission, but visible light does not have the same effect.
  • #1
123kid
18
0
If there is continue emission of electrons from surface then what will
be its effect on that surface? Some of my friends told me that there are
billions billions electrons. Nothing happen. But i think there is also emission of billions of electrons within small time. Can this process make a deficiency of electrons on the surface ? Can it completely remove all the electrons?
 
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  • #2
No. As you remove more electrons, you are leaving behind more positive charge, which will prevent further electron removal. You will need more and more energy to remove more electrons.
 
  • #3
123kid said:
If there is continue emission of electrons from surface then what will
be its effect on that surface? Some of my friends told me that there are
billions billions electrons. Nothing happen. But i think there is also emission of billions of electrons within small time. Can this process make a deficiency of electrons on the surface ? Can it completely remove all the electrons?
the object will have less electrons hence becomes positively charged. the increased potensial will cause higher limit of foton energy to free more electron until it stops the electron emission.
you can find a video in youtube where a gold leaf electrode is exposed to ultraviolet radiation then the leaf spreads out. when the radiation is visible light the leaf doesn't move.
 

1. What is thermionic emission and how does it affect surfaces?

Thermionic emission is the process in which electrons are released from a material due to its high temperature. This effect can cause changes in the surface properties of the material, such as increased surface roughness and changes in surface chemistry.

2. What are some applications of thermionic emission effects on surfaces?

Some common applications include thermionic emission microscopy, in which the emission of electrons from a heated source is used to image the surface of a material, and thermionic emission coating, where the emission of electrons is used to deposit a thin film onto a surface.

3. How does the temperature affect thermionic emission on surfaces?

The rate of thermionic emission increases with increasing temperature, as more electrons have enough energy to overcome the surface potential barrier and escape from the material. This effect can also be influenced by the type of material and its surface properties.

4. Can thermionic emission have a negative impact on surfaces?

Yes, in some cases, thermionic emission can lead to degradation or damage of the surface. This is particularly relevant in electronic devices, where the emission of electrons can cause unwanted effects such as surface charging or material erosion.

5. How can thermionic emission effects on surfaces be controlled or minimized?

To control or minimize thermionic emission effects, materials with low work function (the amount of energy required for an electron to escape from the surface) can be used. Additionally, proper cooling mechanisms can be implemented to reduce the temperature of the material and therefore decrease the rate of thermionic emission. Surface treatments and coatings can also be applied to modify the surface properties and reduce the emission of electrons.

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