Seebeck Coefficient / Electric Resistivity
Seebeck Effect / Electric Resistivity
Thermoelectricity describes the direct conversion of a temperature gradient into electricity and vice versa. The Seebeck effect was discovered by J. T. Seebeck, a German physicist in 1821 and describes the formation of an electric field at an applied temperature gradient. In reversal of this, the Peltier effect causes a temperature gradient by applying a current flow to a given setup.
The efficiency of the electrical and thermal conversion ability of a material is described by the dimensionless Thermoelectric Figure of Merrit ZT = (σ*S2 / λ) * T in which σ*S2 is the so called power factor (consisting of electrical conductivity and Seebeck coefficient) and λ is the thermal conductivity. All these parameters are temperature dependent material properties.
In the face of recent global warming caused by carbon dioxide and depletion of fossil fuels, thermoelectric conversion devices are attracting attention because of its effective utilization of waste heat energies. But also for cooling applications using the Peltier effect, thermoelectric characterization is very important.
To meet these pressing requirements, characteristic evaluating instruments for these materials and devices have been developed. The LSR-3 Seebeck Coefficient measurement and electric resistivity measurement unit, working in a temperature range from -100°C up to 1500°C as well as the XFA Xenonflash and LFA Laserflash apparatus for thermal conductivity determination in the temperature range from -125°C up to 2800°C.