Correlation Between Laser-Induced Surface Acoustic Waves and Nanoindentation on Elastic Modulus Measurement of a Nanoporous Zeolite Thin Film

Porous thin films are challenging for mechanical characterization due to their soft, thin, and delicate nature. In this study, a nanoporous zeolite thin film is characterized with both laser-induced surface acoustic wave technique (LiSAW) and nanoindentation. The LiSAW technique measured moduli of 38 GPa and 35 GPa for the non-calcined and calcined zeolite films respectively, whereas the respective nanoindentation results of 51 GPa and 47 GPa demonstrated significant substrate influence even at indentation depths within 10 % of film thickness. More accurate indentation results were achieved through an alternative indentation analysis scheme, but at the cost of significant computation time. The results show the distinctive advantage of the LiSAW technique on porous thin films while demonstrating the challenges and current adaptations of traditional nanoindentation.