# Thermal conductivity of SiC and the mechanisms

1. Aug 23, 2016

### Carlos de Meo

Hi Guys
I was studying the thermal properties of SiC at high temperatures and now i have a few questions
Usually, at high temperatures, the photons effect are much more intense than phonons at high temperature, correct?
According to Rosseland heat diffusion equation
Krad = 16σT3 /3β, β= 4πK/λ, σ is the steffan-boltzman constant,β the absorption coefficient and k the extinction coefficient
From the literature, i found the following numbers for the SiC: k= 10-2 for λ= 2 μm
Using these values in the Rosseland equation, Krad is smaller than 1 W/(mK)-1 but from the literature the measured value for SiC thermal conductivity at high temperatures (around 1000 °C) is around 20 W/(mK)-1. Is it due to pure phonons effect or am i missing another effect ?

2. Aug 25, 2016