Temperature dependent thermal conductivity of IIa diamond by laser excited Raman spectroscopy

Abstract

The thermal conductivity of IIa diamond from low temperature (80 K) to room temperature was studied by laser-excited Raman spectroscopy. The laser has two complementary effects, one performing the Raman spectrum and the other resulting in the local heating on the surface of diamond. With the increase in measurement temperature on the surface of IIa diamond, the Raman peak shifts to the low energy side together with intensity quenching due to the strong electron-phonon coupling and lattice expansion, and the thermal conductivity of IIa diamond decreases as T-1, which is attributed to the creation and the annihilation of phonons.