Measuring methods applicable to Thermoelectric Materials: Fraunhofer-IPM capabilities and services

Abstract

Over the past decade Fraunhofer-IPM implemented various measurement techniques applicable to thin films and bulk materials. Fraunhofer-IPM is now developing customer-oriented measurement systems especially adapted for thermoelectric materials. They are combining accuracy, rapidity, little efforts for sample mounting, and are fully automated as far as the data acquisition is concerned. The following measurement techniques and their implementation at IPM will be presented: an integrated (acquisition and data interpretation) 3 omega-system for the measurement of the thermal conductivity and heat capacity, two push-button measuring-stations for the measurement of the electrical conductivity and the Seebeck coefficient at room temperature, and a new fully automated station for the measurement of the Seebeck coefficient at high temperatures. For the last mentioned measurement method, which will be discussed in detail, pressure contacts are used for contacting the thermocouples to the sample and the sample to the heat sink, making the measurement of both thin films and bulk materials possible, with a great flexibility on their geometrical dimensions. Finally, the validation of all methods is discussed in terms of suitability and availability of test-samples