Pressure dependence of Raman phonons of Ge and 3 C -SiC

摘要: The pressure dependence of several Raman lines Ge and $3C$-SiC has been studied up to 11 GPa with a gasketed diamond anvil cell. A nonlinear the $\mathrm{TO}(\ensuremath{\Gamma})$ frequencies on softening $\mathrm{TA}(X)$ modes have observed. Gr\"uneisen parameters optical acoustical phonons corresponding critical points at edges zone determined. linewidths long-wavelength increase for pressures above 10 GPa. This observation is interpreted in terms an decay rates $\ensuremath{\Gamma}$ into two modes.