ELASTIC CONSTANTS AND SP2-BONDED REGION OFNANOCRYSTALLINE DIAMOND THIN FILMS

摘要

This paper studies the relationship between anisotropic elastic constants and sp~2-bonded regions of nanocrystalline diamond thin films, which were deposited by the CVDmethod adding N_2gas.The elastic constants were measured by resonant ultrasoundspectroscopy coupled with laser-Doppler interferometry, and the pump-probe method usingfemtosecond-pulse laser to detect Brillouin oscillations. We developed the micromechanicscalculation to explain the results, which shows that the off-diagonal elastic constants have strongcorrelation with the sp~2-bonded regions.