Abstract
The elastic constants and of single-crystal NaCl-structure layers, with ranging from 0.67 to 1.0, were determined using sound velocity measurements. Picosecond ultrasonic optical pump/probe techniques were employed to generate and detect longitudinal sound waves and surface acoustic waves (SAW) in order to obtain and , respectively. SAW generation was achieved by depositing a periodic series of Al bars on the layers to spatially modulate the surface reflectivity. and were found to decrease continuously from 626 and with to 439 and with . The Voit–Reuss–Hill average aggregate elastic moduli obtained from our measured and values are in good agreement with previous nanoindentation results.
- Received 11 November 2004
DOI:https://doi.org/10.1103/PhysRevB.71.144106
©2005 American Physical Society