Polycrystalline Graphite — Thermal Conductivity
Graphite materials are known to show a maximum thermal conductivity around room temperature, which can easily be analyzed using the low temperature version of the LFA 457 MicroFlash®. The physical explanation for this maximum is the high Debye temperature of this material (> 1000 K). The decrease in thermal diffusivity with increasing temperature dominates the temperature dependence of the thermal conductivity in the high temperature region. The specific heat decreases stronlgy at temperatures below room temperature and dominates the temperature dependence of the thermal conductivity there.