Apparatus for Seebeck coefficient measurement of wire, thin film and bulk materials in the wide temperature range (80-650K)

TL;DR

This paper presents a versatile apparatus capable of accurately measuring the Seebeck coefficient of various sample types across a wide temperature range, simplifying complex measurements for different geometries and materials.

Contribution

The authors designed a novel, multi-sample compatible Seebeck measurement system that covers wires, thin films, and pellets from 80 to 650K, with simplified sample handling and calibration.

Findings

Accurate Seebeck measurements for standard samples like constantan and GaN.

Effective measurement of diverse sample geometries and resistivity ranges.

Calibration results consistent with established data.

Abstract

A Seebeck coefficient measurement apparatus has been designed and developed, which is very effective for accurate characterization of different type of samples in a wide temperature range (80 - 650K) simultaneously covering low as well as the high-temperature regime. Reducing the complexity of the technical design of sample holder and data collections has always been challenging to implement in a single instrument when samples are in different geometrical shape and electronic structure. Our unique design of sample holder with pressure probes covers measurements of different samples shapes (wires, thin films and pellets) as well as different resistivity ranges (metals, semiconductors and insulators). It is suitable for characterization of different samples sizes (3-12 mm). A double heater configuration powered by a dual channel source meter is employed for maintaining a desired constant temperature difference across the sample for the whole temperature range. Two K-type thermocouples are used for simultaneously reading of temperatures and Seebeck voltages by utilizing different channels of a multichannel digital multimeter. Calibration of the system has been carried out using constantan, chromel and alumel materials and recorded data is found to be very accurate and consistent with earlier reports. The Seebeck coefficients of standard samples of constantan (wire) and GaN (thin film) have been reported, which shows the measurement capability of designed setup with versatile samples.