A straightforward 2ω technique for the measurement of the Thomson effect

Area of Science:

• Thermoelectricity
• Materials Science
• Electrical Engineering

Background:

• The Thomson coefficient is a crucial parameter in understanding thermoelectric phenomena.
• Accurate measurement of the Thomson coefficient is essential for developing advanced thermoelectric materials and devices.
• Existing methods for measuring the Thomson coefficient can be complex and time-consuming.

Purpose of the Study:

• To present a simplified, rapid, and accurate method for measuring the thermoelectric Thomson coefficient.
• To enable high-precision extraction of the absolute thermoelectric coefficient of single materials.
• To identify and analyze the primary sources of error in the proposed measurement technique.

Main Methods:

• Dynamical heating of a suspended wire using an alternating current.
• Application of a temperature gradient across the wire.
• Measurement of the response at the second harmonic of the excitation frequency using a phase-sensitive detector.

Main Results:

• The response at the second harmonic of the excitation frequency is directly proportional to the Thomson coefficient.
• The proposed method allows for high-precision determination of the absolute thermoelectric coefficient.
• The method was successfully tested on platinum and nickel wires.
• Analytical and numerical models were developed to assess error sources.

Conclusions:

• The presented method offers a simplified, rapid, and accurate approach for Thomson coefficient measurement.
• This technique facilitates precise determination of a key thermoelectric property for various materials.
• The developed models aid in understanding and mitigating errors, enhancing the reliability of the measurements.