In an attempt to identify the kind of disorder that leads to glasslike lattice vibrations in certain crystals, we have studied the low-temperature elastic properties of Ag:Zn and Cd:Mg alloys known to show Zener relaxation, which is believed to result from the relaxation of elastic dipoles. Although low-energy excitations were found, they are different from those observed in other crystals in which glasslike excitations have been previously reported.

• Received 22 May 1992

DOI:https://doi.org/10.1103/PhysRevB.46.10657