Talk:Pyroelectricity

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Template:Physics Template:WikiProject Energy Piezoelectric effect redirects to piezoelectricity, and pyroelectric effect redirects to pyroelectricity, but ferroelectricity redirects to ferroelectric effect. These should all be consistent. The "-ity" sounds rather odd to me, and I think " effect" is better. Any opinions? –radiojon 15:03, 2004 Apr 16 (UTC)

I like "effect" better, too. - Omegatron 00:16, Feb 12, 2005 (UTC)
"effect" is trite and useless. 69.106.153.67 14:45, 28 Apr 2005 (UTC)

I changed the wording. This is technically not the same thing that 'cold fusion' was looking at doing.

Pyroelectric efficiency?

What is present and projected efficiency of pyroelectric energy conversion devices? —Preceding unsigned comment added by Stanley 70.73.149.123 (talk) 05:37, 31 May 2009 (UTC)

I had never heard of a pyroelectric energy conversion device, but I looked it up, and a few people have looked into it. I added a small section to the article. If anyone knows or finds out more about it, they should edit that section. --Steve (talk) 18:00, 31 May 2009

(UTC)

Thanks for answer! If this is true that conversion efficiency could be as high as 84-91%,this is the best known thermal conversion efficiency! Unfortunately,in other places I found statements that conversion efficiency is rather small,but could be improved with Ericsson cycles [1].Maybe efficiency is very different for different materials.It is really wandering that there is no widespread rumor about pyroelectrics.If they could achieve 80-90% efficiency,all those platinum fuel cells have no any sense as well as efforts put in their development.I think that farther verification is needed.And also, do pyroelectic efficiency increase with increase in temperature of heat source? I read they could be stable at 1200 OC. Stanley

Platinum fuel cells aren't really a fair comparison. Fuel cells turn hydrogen and oxygen directly into water and electrical energy. For a pyroelectric, you need to heat it, cool it, heat it, cool it, and you get energy. It functions like the working fluid of an electrical generator, which pushes a piston and rotates a magnet to generate electricity. It's less efficient than the piston-systems of coal power plants, for example. In other words, there are a lot of losses associated with repeated heating and cooling, and that's not included in the 84-91% figure. --Steve (talk) 01:25, 6 June 2009 (UTC)

There is also interesting article: [2] They also mention 80-90% efficiency for similar principles. Maybe there could be some pyroelectrics which maintain electric potential permanently (similar to thermoelectrics?) Stanley —Preceding unsigned comment added by 70.73.149.123 (talk) 02:03, 6 June 2009 (UTC)

Relationship between pyroelectricity and the Peltier-Seebeck effect

What is the relationship between pyroelectricity and the Peltier-Seebeck effect? - Omegatron 03:23, May 19, 2005 (UTC)

In pyroelectricity you have a change in the spontaneous polarization due to heating/cooling the material. In the Peltier-Seebeck effect, it is a potential difference generated as a result of a temperature difference between two sides of a material. I have added the equations for pyroelectricity, so you can compare these equations with those in the Peltier-Seebeck effect. --Nathaniel (talk) 10:43, 30 June 2008 (UTC)

The side between electrical and thermal corners represents the pyroelectric effect and produces no kinetic energy. The side between kinetic and electrical corners represents the piezoelectric effect and produces no heat.

What is the side between thermal and kinetic? - Omegatron 15:33, May 19, 2005 (UTC)

Pyroelectricity is not electric potential

(I'm not native speaker.)

In the very first phrase "Pyroelectricity refers to..." seems to me better than "Pyroelectricity is...". Want to say that pyroelectricity is NOT potential but an effect where potential arises if...

Any sugestions?

I agree, pyroelectricity is not electrical potential. It is the change of spontaneous polarization with temperature. I would think that the change in spontaneous polarization would generate an electrical potential, though. Note that the electrical potential may also result in current flow. --Nathaniel (talk) 01:36, 10 July 2008 (UTC)

Mathematical treatment of pyroelectricity

There seems to be no discussion of how pyroelectrics are modeled, e.g. that the pyroelectric coefficient p of a material is given by :

where is the change in polarisation, and the change in temperature. Is this simply missing or is it in a separate article ? --ACH 15:43, 4 December 2005 (UTC)

I'm not sure if this is in a separate article (I did not find it). However, I have put in the relevant equations. Note that the pyroelectric coefficient is a tensor, and partial derivatives are involved. --Nathaniel (talk) 10:36, 30 June 2008 (UTC)

References

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