Seebeck Coefficient (Thermoelectric Power) Measurements

​

The ProboStat can be used to measure Seebeck coefficient in many ways. The standard method is to suspend a bar sample between two thermocouple tips and measure temperatures at both ends and then the sample voltage between the + or - leads of the thermocouples, or use separate electrodes for sample voltage measurement as in the picture.

Temperature gradient over the sample is either naturally occurring furnace gradient or one induced by small internal heater placed above the spring load top plate. This method can also be used in combination with 4-point conductivity measurement.

This method can be done from ambient temperature up to 1600ºC, from vacuum to high pressure (high pressure option), with any type of gas atmosphere.

​

Best results are achieved with bar sample of 3-4 cm length. Sample may be of arbitrary shape but it is easier to mount if the sample is bar shaped with longer length than cross section. Disc and thin film samples are not mounted as easily as bars and the electrode contacts may have to be glued (with Pt ink) to the side (since the film only covers the side and not the ends of the sample).

​

There is no clear limit how small samples can be measured, but as the sizes go smaller the mounting gets harder and more importantly the ratio between signal and error gets less favorable.