Instrument for simultaneous measurement of Seebeck coefficient and thermal conductivity in the temperature range 300-800 K with python interfacing

TL;DR

This paper presents a Python-controlled instrument capable of simultaneously measuring Seebeck coefficient and thermal conductivity of various samples from 300 to 800 K, with validated accuracy and versatility.

Contribution

The work introduces a simple, robust, and customizable instrument for high-temperature thermoelectric measurements using Python automation and accessible components.

Findings

Measured Seebeck coefficient range: -20 to 600 μV/K

Thermal conductivity range: 1.1 to 23.5 W/m-K

Validated measurements on multiple sample types

Abstract

Fabrication and characterization of instrument for high-temperature simultaneous measurement of Seebeck coefficient (S) and thermal conductivity ($\kappa$) has been carried out with python automation. The steady-state based Fourier's law of thermal conduction is employed for $\kappa$ measurement. The parallel thermal conductance technique is implemented for heat loss measurement. Introducing the thin heater and insulating heater base minimize the heat loss and make the way easier to arrive at high temperature. Measurement of S is carried out using differential method. Same thermocouples are used to measure temperature as well as voltage for S measurement. Care of temperature dependent S of thermocouple has also been taken. Simple design, small size, lightweightmake this instrument more robust. All the components for making sample holder are easily available in the market and can be replaced as per the user demand. This instrument can measure samples with various dimensions and shapes in the temperature range 300 $-$ 800 K. The instrument is validated using different class of samples, such as nickel, gadolinium, Fe$_{2}$VAl and LaCoO$_{3}$. Wide range of S from $\sim$ $-$20 to $\sim$600 $\mu$V/K and $\kappa$ from $\sim$1.1 to $\sim$23.5 W/m-K are studied. The measured values of S and k are in good agreement with the reported data.