About this Engineering article
Pulse Laser Acoustics for the Characterization of Inhomogeneities at Interfaces of Microstructures by Jacqueline Vollmann; Dieter M Profunser; Andreas H Meier; Max Döbeli; Jürg Dual is a Engineering article available to read on EtoBox.
Interfaces between neighbouring materials are often subjected to diffusion processes which cause layers having gradually varying mechanical properties--like densities, Young's moduli or shear moduli--perpendicular to the surface or interface. In this investigation particular interest is drawn on the question how the propagation characteristics of bulk acoustic waves are affected by diffusion layers. The reflection and transmission behavior of bulk acoustic waves encountering a continuum having a spatially dependent sound velocity is discussed based on numerical simulations as well as on experimental verifications. The simulated results are part of an on-going project in which material properties of MEMS devices are investigated by short pulse laser acoustic methods. Mechanical waves are excited and detected thermoelastically using laser pulses of 70 fs duration. For metals this leads to wavelengths of 10-20 nm and the corresponding frequencies amount to 0.3-0.6 THz. In contrast to previous work done in this field in which diffusion effects are generally considered as undesirable phenomena, the deliberate realization of microstructures having well defined gradually varying material
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- Author
- Jacqueline Vollmann; Dieter M Profunser; Andreas H Meier; Max Döbeli; Jürg Dual
- Publisher
- Elsevier Science; Elsevier ; Elsevier BV (ISSN 0041-624X)
- Published
- 2004
- Language
- EN
- Field
- Engineering (Physical Sciences)