SBA 458 Nemesis®
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Simultaneous Determination of the Seebeck Coefficient and Electrical Conductivity -SBA 458 Nemesis® Method and Technique for the Characterization of Thermoelectric Materials Analyzing & Testing

Your Partner In Testing Thermoelectrics Thermoelectric materials with high working temperatures and optimized efficiency are under development for the generation of electrical energy from heat which has been released to the environment. Thereby, precise knowledge of the thermal properties is of paramount importance in order to develop beneficial thermoelectrics with high electrical conductivities, large Seebeck coefficients, and low thermal conductivities. The relative performance or efficiency of a thermoelectric material is described by the figure of merit (ZT): S2 σ ZT = ( ––––– ) T λ S...

A NEW METHOD WITH INNOVATIVE DESIGN The SBA 458 Nemesis® is a truly new method for determination of the Seebeck coefficient (S) and electrical conductivity (σ). Its novel setup and clever, practical design offer numerous unparalleled advantages. Perhaps the most significant of these is elimination of the disadvantages inherent in conventional methods – thus allowing for the reliable and precise determination of the two thermophysical properties S and σ. support heater Measurement setup of the SBA 458 Nemesis® for the temperature range between RT and 800°C A Clever New Setup Using current...

Yields Advantages Plug-and-Measure The new plug-and-measure feature offers convenient sample change. The operator may now use various sample geometries in different dimensions. Since distance determination between the thermocouples is no longer required, a quick start to the measurement can be realized. Robust, Flexible and Reliable In every respect, the robust design of the SbA 458 Nemesis® allows for unfettered, easy handling. The thermocouples are exceptionally well protected against damage by virtue of Inconel® sheathing, and are additionally mechanically fixated in order to yield high...

Need to measure on a variety of sample geometries – including thin films? Tired of complicated sample positioning? Prefer to start your measurement quickly? Want to eliminate a common source of error by measuring the distance between the thermocouples? The Solution! The One and Only for Different Sample Geometries Easy and Fast Sample Change No Tools No Distance Determination

No Distance Determination Required Distance determination between fixed thermocouple positions is a cumbersome process which is usually necessary, but this instrument eliminates the need for any operator handling in this regard. By excluding this potential source of error from the determination process for electrical conductivity, the precision and reproducibility of the results are increased. Measurement Setup for Varied Sample Geometries The hallmark of the SBA 458 Nemesis® is its one-of-a-kind measurement setup which allows more sample geometries than usual for this technique. Depending...

ROBUST SYSTEM contamination of the measuring junction Reduced risk of thermocouple damage No moving of thermocouples Constant contact force Simple change of thermocouples and current pins

Mechanical Fixation of Thermocouple Positions The thermocouple positions are fixated, thus eliminating any requirement for distance determination between them. By excluding this potential source of error from the determination process for electrical conductivity, the precision and reproducibility of the results increase considerably. Inconel-Sheathed Thermocouples Temperature (voltage) measurements are carried out via two sheathed thermocouples. The Inconel® sheathing prevents chemical contamination of the measuring junction and also prevents any adhesion between the thermocouple and the...

The unique design of the SBA 458 Nemesis® allows for a quality check of both the Seebeck coefficient and electrical conductivity. Even before a time-consuming temperature program is started, this quality check indicates whether a measurement can be performed without any errors. In addition, the quality check is performed at each temperature step, monitoring the correctness of the measurement results for the Seebeck coefficient and the electrical conductivity. Quality Check Offers Contact Check Detection of Inhomogeneity Detection of Barrier Layer Optimized Testing Time INTEGRATED QUALITY...

The Two Readings of the Quality Check Seebeck Coefficient Electrical Conductivity A temperature gradient is generated in both sample directions by two micro heaters operating in alternation. While the cyclic heating is in progress, the resulting voltages (UA, UB) are measured. UA and UB are the voltages between the two positive and two negative thermocouple wires which are plotted against the temperature difference (ΔT; for both directions). ΔT is determined by two thermocouples (plot A). At each testing temperature, different current values will be applied to the sample several times by...

Comparison with Literature Values Bi-Doped PbTe Physikalisch-Technische Bundesanstalt Braunschweig und Berlin (The National Metrology Institute of Germany) This plots portrays the Seebeck coefficient (green curve) and electrical conductivity (blue curve) between room temperature and 250°C. The dotted green line represents the literature values1. Good correlation can be observed, indicating the reliability of the system. Lead telluride exhibits good performance as a thermoelectric material, due in part to its low thermal conductivity and in part to its electrical properties.

Half-Heusler Recently, Heusler and Half-Heusler compounds gained significant attention due to their wide range of extraordinary functionalities. They are attractive as half-metallic high-temperature ferri- and ferromagnets, multiferroic shape-memory alloys, etc., and very promising for usage in thermoelectric generators (TEGs) for energy harvesting from any heat source. In the range between room temperature and 480°C, the Seebeck coefficient of the investigated p-ZrHfCoSbSn material reaches up to 175 μV/K. In the same temperature range, the electrical conductivity drops from 1260 S/cm to...