Nanomechanical investigation of thin-film electroceramic/metal-organic framework multilayers
Best, J. ,P. / Michler, J. / Liu, J. / Wang, Z. / Tsotsalas, M. / Maeder, X. / Rose, S. / Oberst, V. / Liu, J. / Walheim, S. /Gliemann, H. / Weidler, P. , G. / Redel, E. /Wöll, C. (2015)
APPLIED PHYSICS LETTERS (2015), 107, 101902
- Date: September 2015
Thin-film multilayer stacks of mechanically hard magnetron sputtered indium tin oxide (ITO) and mechanically soft highly porous surface anchored metal-organic framework (SURMOF) HKUST-1 were studied using nanoindentation. Crystalline, continuous, and monolithic surface anchored MOF thin films were fabricated using a liquid-phase epitaxial growth method.
Control over respective fabrication processes allowed for tuning of the thickness of the thin film systems with a high degree of precision. It was found that the mechanical indentation of such thin films is significantly affected by the substrate properties; however, elastic parameters were able to be decoupled for constituent thin-film materials (Erro≈ 96.7 GPa,EHKUST-1≈ 22.0 GPa). For indentation of multilayer stacks, it was found that as the layer thicknesses were increased, while holding the relative thickness of ITO and HKUST-1 constant, the resistance to deformation was significantly altered.
Such an observation is likely due to small, albeit significant, changes in film texture, interfacial roughness, size effects, and controlling deformation mechanism as a result of increasing material deposition during processing. Such effects may have consequences regarding the rational mechanical design and utilization of MOF-based hybrid thin-film devices.