Phonon transmission from incoherent radiators into quartz, sapphire, diamond, silicon and germanium within anisotropic continuum acoustics

Abstract

The phonon excitation in monocrystals by phonon transmission from an adjacent incoherent phonon radiator is treated within continuum acoustics for several crystal cuts of sapphire, quartz, diamond, silicon and germanium. Whereas the theoretical treatment is made as general as possible, in numerical computation the radiator material is assumed to be mechanical isotropic, the monocrystal however anisotropic. For a diffuse phonon field with equilibrium distribution between the different polarizations in the radiator, the$\vec q$-space phonon intensity in the crystal substrate is calculated and presented graphically for the most important cases. Numerical values of halfspace emissivities as well as of the differential emissivities normal to the crystal faces are given for a large variety of material combinations.