Thermocyclic stability of candidate Seebeck coefficient Standard Reference Materials at high temperature
Joshua B. Martin, Winnie K. Wong-Ng, Thierry Caillat, Ichiro Yonenaga, Martin L. Green
The Seebeck coefficient is the most widely measured property specific to thermoelectric materials. Presently, there is no consensus on measurement protocols and researchers employ a variety of techniques to measure the Seebeck coefficient. The implementation of standardized measurement protocols and the use of reliable Seebeck Coefficient Standard Reference Materials (SRMs®) will allow the accurate interlaboratory comparison and validation of materials data, thereby accelerating the development and commercialization more efficient thermoelectric materials and devices. To enable members of the thermoelectric materials community the means to calibrate Seebeck coefficient measurement equipment, NIST recently certified SRM® 3451 Low Temperature Seebeck Coefficient Standard (10 K - 390 K). Due to different practical requirements in both instrumentation and sample contact methodology, a complementary SRM is required for the high temperature regime (300 K 900 K). The principle requirement of a SRM for the Seebeck coefficient at high temperature is thermocylic stability. We therefore characterize the thermocyclic evolution of the Seebeck coefficient for a series of candidate materials: constantan, p-type single crystal SiGe, and p-type polycrystalline SiGe, by measuring the temperature dependence of the Seebeck coefficient as a function of 10 sequential thermal cycles, between 300 K and 900 K. We then employ multiple regression analysis via parametric models to interpolate and analyze the thermodynamic variability in the irregularly sampled measurement curves.
, Wong-Ng, W.
, , T.
, Yonenaga, I.
and Green, M.
Thermocyclic stability of candidate Seebeck coefficient Standard Reference Materials at high temperature, Journal of Applied Physics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=915230
(Accessed December 3, 2023)