SECLUDED SUPERSONIC SURFACE-WAVES IN GERMANIUM

A secluded supersonic SAW is known to exist in an isolated direction o n the (001) surface of certain cubic crystals. This wave consists of t wo evanescent partial wave components and is not polarized in a symmet ry plane. Calculations are reported on this mode, using germanium as a n example, and it is found that this wave continues to exist for some surface orientations different from (001). A one dimensional family of nonsymmetrical supersonic SAW geometries is identified and it is foun d to be joined to the family of supersonic SAW polarized in the (1 $($ ) over bar$$ 10) symmetry plane.