Thermoelectric power measurements on graphite pencil lead and traces

Abstract

Inducing a temperature difference across a conductor causes the generation of an internal electric field owing to the diffusion of carriers from the hotter side to the colder side. This is known as the thermoelectric effect whose origin is the simultaneous transfer of thermal energy and electric charge by the carriers when phonon effects are negligible. In this study, the thermoelectric transport properties were investigated using conventional bulk graphite pencil lead and pencil traces formed by drawing on the alumina plate with the same pencil lead. Two different thermoelectric power measurement techniques—steady-state DC and slowly varying AC—were employed in a single-device setup to systematically examine this phenomenon, demonstrating consistent results. We believe that the thorough verification of thermoelectric power using the two techniques is virtually unique and may provide additional insight into the measurement of elusive thermal transport phenomena emerging from delicate changes in the density of states near the Fermi level in the physics of correlated electrons. © 2023, The Korean Physical Society.