Piezoelectric waves near an imperfectly bonded interface between two half-spaces

We show the existence of certain waves propagating near an imperfectly bonded interface between two half-spaces of different piezoelectric ceramics. Some of the waves reduce to known waves when perfect bonding is assumed. There are also waves that rely on the imperfection of the interface bonding and they do not remain as interface waves when the bonding is perfect. In particular, it is shown that interface imperfection causes dispersion in general, although there does not explicitly exist a geometric characteristic length of the two-half-space structure. The theoretical results obtained can also be used to design experiments for measuring interface properties.