Definitions for "Thermal conductivity"
The property of a material that describes how well heat passes through it.
The thermal conductivity of a substance is the quantity of heat in cal/sec passing through a body 1 cm thick with a cross section of 1 sq. cm when the temperature difference between the hot and cold sides of the body is 1 deg. C.
The rate at which heat is conducted through a solid at 'steady state' (meaning that the temperature profile does not change with time) is governed by the thermal conductivity. It is measured by recording the heat flux J (W/m²) flowing from surface at temperature T1 to one at T2 in the material, separated by a distance X.
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46 W/m/K Properties at temp=300 K,wavelength not given for refractive index Semiconductor Sensors,by S.M.Sze,UMC chair professor,John Wiley & Sons ,INC.Appendix D, p.535