Experimental Setup for the Measurement of the Thermoelectric Power in Zero and Applied Magnetic Field

TL;DR

This paper presents a versatile, accurate, and automated experimental setup for measuring thermoelectric power across a wide temperature and magnetic field range, enabling high-density data collection efficiently.

Contribution

The paper introduces a new experimental system capable of rapid, high-precision thermoelectric power measurements in magnetic fields up to 140 kOe and temperatures from 2 to 350 K.

Findings

High-density TEP data can be acquired quickly.

System calibration shows good agreement with literature.

TEP measurements on specific materials demonstrate magnetic field response.

Abstract

An experimental setup was developed for the measurement of the thermoelectric power (TEP, Seebeck coefficient) in the temperature range from 2 to 350 K and magnetic fields up to 140 kOe. The system was built to fit in a commercial cryostat and is versatile, accurate and automated; using two heaters and two thermometers increases the accuracy of the TEP measurement. High density data of temperature sweeps from 2 to 350 K can be acquired in under 16 hours and high density data of isothermal field sweeps from 0 to 140 kOe can be obtained in under 2 hours. Calibrations for the system have been performed on a platinum wire and Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ high $T_{c}$ superconductors. The measured TEP of phosphor-bronze (voltage lead wire) turns to be very small, where the absolute TEP value of phosphor-bronze wire is much less than 0.5 $\mu$V/K below 80 K. For copper and platinum wires measured against to the phosphor-bronze wire, the agreement between measured results and the literature data is good. To demonstrate the applied magnetic field response of the system, we report measurements of the TEP on single crystal samples of LaAgSb$_{2}$ and CeAgSb$_{2}$ in fields up to 140 kOe.