Why does seebeck effect occur

The heat moving at the end of the applied electric current creates heating on one surface and cooling on the other Image 2. Thermoelectric cooling system operates silently due to the absence of dynamic parts during the cooling period. Three types of thermoelectric effects occur simultaneously in the circuit by passing electrical current through the circuit created by combining two different semiconductor materials with chemical methods.

These three effects are called by the names of the inventors. These are Seebeck, Peltier and Thomson effects. In the circuit, which is formed by combining two different semiconductor materials in series, the electrical voltage is measured at different temperatures. The measured voltage in the circuit is directly proportional to the temperature difference between the surfaces of the materials.

The resulting seebeck effect is used as a generator in semiconductors and as a thermocouple or temperature sensor in metals. It was discovered in that DC current was passing over two different semiconductor materials and creating heat in the direction in which the current was moving by French physicist Jean Charles Athanasa Peltier. This effect is called the Peltier effect. In order to generate power with the a thermoelectric generator you need both a heat source and a way of dissipating heat in order to maintain a temperature difference across the thermoelectric materials.

This is done with no moving parts by heating water in the PowerPot. Water holds several times more heat than aluminum per pound, so it makes a wonderful heatsink. This is why you always need to have something watery in the PowerPot or else it is possible to overheat the thermoelectric generator.

This rendering shows temperature distribution in the PowerPot during operation with some parts removed for clarity. Thermoelectric power is the conversion of a temperature differential directly into electrical power. Thermoelectric power results primarily from two physical effects: the Seebeck effect , and Peltier effect. The Seebeck effect is named after Thomas J. Seebeck, who first discovered the phenomenon in Seebeck noticed that when a loop comprised of two dissimilar materials was heated on one side, an electromagnetic field was created.

He actually discovered the EM field directly with a compass! He noted that the strength of the electromagnetic field, and therefore the voltage, is proportional to the temperature difference between the hot and cold sides of the material which creates a voltage difference. The magnitude of the Seebeck coefficient S varies with material and temperature of operation.

The Seebeck coefficient is thus defined as:. So, to answer your question, yes, materials A and B are doing opposite thing and the reason is that they have opposite charge carriers.

So the overall voltage will be reduced. You can however introduce a third material, and your conclusion would hold if it was placed along the cold and hot sides.

And this is precisely what people do when building a thermoelectric generator TEG to link the p and n-type legs. Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Learn more. Understanding the Seebeck effect Ask Question. Asked 9 years, 11 months ago.

Active 2 years, 11 months ago. Viewed 3k times. Questions: How do you make a series circuit with lots of thermocouples? Improve this question. Dov Dov 2 2 gold badges 10 10 silver badges 18 18 bronze badges. Edit one out of this post and then make it into a new post. You can link to this one to provide the context. Add a comment. Active Oldest Votes. It's connected like this: Suppose you take two materials with an electropotential: Cobalt and Lithium. B 97 , Shiomi, Y.

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Indirect coupling of nuclear spins in antiferromagnet with particular reference to MnF2 at very low temperatures. Nuclear magnetic resonance modes in magnetic material. King, A. Nuclear magnons and nuclear magnetostatic modes in MnF 2.

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B 90 , Cornelissen, L. Nonlocal magnon-polaron transport in yttrium iron garnet. B 96 , Download references. We thank Y. Chen, J. Lustikova, T. Hioki, N. Yokoi, H. Chudo, M. Imai, K. Sato, and G. Bauer for fruitful discussions and T. Nojima for his valuable comments on low-temperature experiments. Kikkawa, H.

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