Surface acoustic waves velocity perturbation in LiNbO3by proton exchange

It is shown that the exchange of Li + ions in LiNbO 3 by protons leads to a large decrease of the (group) velocity of surface acoustic waves propagating in the x-direction on Y- and Z-cut samples. Changes up to about 20% were measured at a frequency of 180 MHz. This effect can be used to construct strip waveguides for surface acoustic waves.