Problems with the determination of elastic constants from higher-order surface waves: Results for Al on NaCl

• DOI: 10.1103/physrevb.37.1007
• Publication Date: 2002-07-27T02:38:00Z
• Authors: F. Nizzoli; R. Bhadra; O. F. de Lima; M. B. Brodsky; M. Grimsditch
• Keywords: 0103 physical sciences; 01 natural sciences

Using Brillouin scattering we have studied the surfacelike generalized Lamb modes in Al films on NaCl. a theory which elastic constants (${C}_{\mathrm{ij}}$) of are taken from bulk values, reasonably good agreement is found for positions peaks. However, were unable to fit our experimental results obtain ${C}_{\mathrm{ij}}$ independently, since different combinations lead similar spectra and dispersion curves. The changes brought about by varying each one investigated theoretically, but no case could linewidths be reproduced. fact that much narrower than calculated ones very hard explain unless it assumed not completely bonded substrate. Calculations unsupported support this explanation. Our clearly show difficulty obtaining information an analysis film substrate illustrate some problems can encountered.