Fabrication of fully automated setup for high temperature thermal   conductivity measurement
  In this work, we report the fabrication of experimental setup for high temperature thermal conductivity ($\kappa$) measurement. It can characterize samples with various dimensions and shapes. Steady state based axial heat flow technique is used for $\kappa$ measurement. Heat loss is measured using parallel thermal conductance technique. Simple design, lightweight and small size sample holder is developed by using a thin heater and limited components. Low heat loss value is achieved by using very low thermal conductive insulator block with small cross sectional area. Power delivered to the heater is measured accurately by using 4-wire technique and for this, heater is developed with 4-wire. This setup is validated by using $Bi_{0.36}Sb_{1.45}Te_3$, polycrystalline bismuth, gadolinium, and alumina samples. The data obtained for these samples are found to be in good agreement with the reported data. The maximum deviation of 6 \% in the value $\kappa$ are observed. This maximum deviation is observed with the gadolinium sample. We also report the thermal conductivity of polycrystalline tellurium from 320 K to 550 K and the non monotonous behavior of $\kappa$ with temperature is observed. 
Ashutosh Patel and Sudhir K. Pandey
physics.ins-det