Emission of light from incandescence of metals

In summary: As for band structure, I don't see how it can affect emission. In summary, the emission of EM radiation from metals when heated or under electric current can be explained through black body radiation. The involvement of electrons and the role of band structure in this phenomenon are still not fully understood.
  • #1
bentzy
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TL;DR Summary
This upload regards two linked questions, as follows: a. what's the detailed mechanism explaining the emission of light from metal.
b. does the classical model of radiation due to decelaration of electrons hold here ?
c. references related to these 2 questions.
a. We know metals emit EM radiation upon heating or electric current. I'd like to understand more fundamentally how this phenomenon takes place, on the basis of the basis of band structure, and which electrons are involved ?
b. Classically, charges emit radiation when accelarating or decelarating. Why doesn't description hold here ? Also, what are the limiting conditions between the description, namely does each hold ?
c. It'll be very kind to get references dealing with these two descriptions, and the questions raised.
Thanks, BC
 
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  • #2
The first stop is black body radiation. It can be understood as the radiated energy from random kinetic motion of charged particles as per b). Metals are excellent absorbers of EM radiation, and so tend to make very good black bodies, however the band structure of some metals e.g. gold can give them a coloured appearance due to the variation in absorption and reflection across the visible spectrum.
 
  • #3
The issues mentioned in your answer are well known, and don't correspond to what asked. Answers should be relevant to the specific aspects & phenomena in question(s).
Thank you for trying.
BC
 
  • #4
bentzy said:
a. We know metals emit EM radiation upon heating or electric current. I'd like to understand more fundamentally how this phenomenon takes place, on the basis of the basis of band structure, and which electrons are involved ?
I suspect all of the electrons are involved, as is the nucleus, since ions, and their corresponding bound electrons, vibrate in place and can move with vibrations and waves within the lattice. I don't think band structure has much to do with blackbody radiation, as a thermal spectrum isn't separated into discrete emission bands.

bentzy said:
b. Classically, charges emit radiation when accelarating or decelarating. Why doesn't description hold here ?
I believe it does to some degree, though I can't say how accurate such a description is.
 
  • #5
bentzy said:
The issues mentioned in your answer are well known, and don't correspond to what asked. Answers should be relevant to the specific aspects & phenomena in question(s).
Thank you for trying.
BC
You asked about metals giving off light when they are heated. That's black body radiation. If it's not the answer you want, perhaps you should rephrase your question instead of being condescending.
 
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  • #6
Claude Bile said:
b). Metals are excellent absorbers of EM radiation, and so tend to make very good black bodies, however the band structure of some metals e.g. gold can give them a coloured appearance due to the variation in absorption and reflection across the visible spectrum.
I wouldn't think so. Metals are good reflectors, at least near the visible range. Their emissivity is about 0.1 (near room temperature), which make them poor black bodies. They get closer to black bodies near their fusion point, but usually they are still far from it.
 

What is incandescence?

Incandescence is the emission of light from a heated object. It is a form of thermal radiation, where the object's temperature causes it to emit visible light.

Why do metals emit light when heated?

Metals emit light when heated because of a phenomenon called blackbody radiation. When the metal is heated, its atoms vibrate at a higher frequency, causing them to emit electromagnetic radiation in the form of visible light.

What is the relationship between temperature and the color of light emitted by metals?

The color of light emitted by metals is directly related to their temperature. As the temperature increases, the color of the emitted light shifts towards the blue end of the spectrum. This is because higher temperatures correspond to higher frequencies of light.

Can all metals emit light through incandescence?

No, not all metals can emit light through incandescence. Only metals with high melting points, such as tungsten, can reach the temperatures necessary to emit visible light through incandescence. Metals with lower melting points, such as aluminum, will melt before reaching these temperatures.

How is the emission of light from incandescence of metals used in everyday life?

The emission of light from incandescence of metals is used in everyday life in various applications. One common example is incandescent light bulbs, where a tungsten filament is heated to emit light. It is also used in industrial processes such as metal welding and in the production of heat-resistant materials.

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