Electron–phonon coupling factor and electron heat capacity of 6H-SiC

Abstract

ABSTRACT For high-energy single ion events, the relationship between electronic energy loss mechanism and atomic processes is generally described by the inelastic thermal spike model. However, the parameters required for the model are not accurately known and are often estimated from a free electron gas model. To ensure this model is more reliable and predictive, a more accurate calculation for the parameters should be taken. In this paper, the temperature dependence of the electronic heat capacity and electron–phonon coupling factor (e-ph) has been calculated, using density functional theory (DFT). The calculation results demonstrate that the effect of electron thermal excitation on the thermodynamic parameters is sensitive to the bandgap, and these parameters vary immensely with the electron temperature. Besides, to verify the accuracy of obtained parameters, both the swift heavy ions (SHI) irradiation in crystalline 6H-SiC and amorphous 6H-SiC are simulated, using the inelastic thermal spike model. And the results are more consistent with the experiment conclusion, for the obtained parameters by DFT. Hence, the calculated temperature-dependent parameters are more suitable for the inelastic thermal spike model.