The 4-probe method has so far been the most popular method for concurrent measurement of Seebeck coefficient and electrical resistivity of bulk samples. However, for Seebeck measurement with higher accuracy, the 2-probe method is becoming preferred over 4-probe method. The problem with the previous apparatus designs is that they do not allow 2-probe arrangement for Seebeck measurement simultaneously with linear 4-probe arrangement for electrical resistivity measurement. So, the challenge is find a design where two different probe arrangements become possible at the same time in a single measurement run. Here, we report design and fabrication of an apparatus that allows Seebeck measurement by 2-probe method concurrently with electrical resistivity by 4-probe method of bar and disc samples in the temperature range from 300 to 1000 K. The uniqueness of the present design is that it does not require heating the entire sample chamber for temperature dependent measurements. This is because a small cylindrical furnace inside the sample chamber is used to control the sample background temperature. This internal furnace arrangement results in readily achievable set temperature with desired uniformity. Thus, it allows faster thermoelectric evaluation of samples. The design includes several preventive steps to negate the effect of off-axial heat flows on the measurement accuracy. The measurement error in Seebeck coefficient and electrical resistivity of PbTe sample is estimated to be smaller than 5%. (C) 2016 Elsevier Ltd. All rights reserved.
Funding Agencies|University Grant Commission (UGC) of India through UGC (NET); Council of Scientific and Industrial Research (CSIR) India through CSIR (NET); Eurostars project [E!8892 T-to-Power]; European Research Council under the European Communitys Seventh Framework Programme/ERC - Belgium [335383]