Influence of the sample mounting on thermal conductance measurements using PPMS TTO option

Abstract

We discuss the performance of the automated heat conductivity measurement system manufactured by the Quantum Design, Inc. The Thermal Transport Option implemented into the Physical Properties Measurement System (PPMS) measures the thermal transport properties of materials (thermal conductivity, Seebeck coefficient and electrical resistivity simultaneously) in the temperature range 1.8 - 395 K and in magnetic fields generated by the installed superconducting solenoid. Recently, discrepancies up to 30% in measured quantities at 390 K have been reported. We critically analyze the experimental method used to measure the above mentioned quantities and show possible sources of problems. © 2009 IOP Publishing Ltd.