The elastic constants and acoustic symmetry of LiYF4

摘要: The elastic behaviour of the scheelite-structure, laser host crystal LiHF4, determined from ultrasonic measurements seven adiabatic stiffness moduli Cijkl between 4.2 and 293K, is expressed in terms acoustic symmetry which occurs such TII Laue crystals. To establish sense Z axis with respect to interatomic arrangement setting angle ( phi s=+29 degrees ) fluorine ion tetrahedron, positions atoms have been by X-ray methods. signs C16 S16 rotation XY plane about axes are established. kappa gamma used together +Z as a basis for set transformed constants C'ijkl. directly compared contrasted oxide scheelites CaWO4, CaMoO4, SrMoO4 PbMoO4.