Speaker
Description
Precise control over crystallographic orientation in metal–organic framework (MOF) thin films is essential for harnessing their functional properties, including anisotropic transport, guest diffusion and flexibility. Aligning the MOF lattice along a defined crystallographic direction enables enhanced, directional performance in applications such as sensing, catalysis, and molecular separation. In this study, we present a fabrication method for the controlled growth of (001)- and (100)-oriented thin films of the model system Zn₂BDC₂DABCO (BDC = terephthalate; DABCO = 1,4-diazabicyclo[2.2.2]octane).
Our spin-assisted layer-by-layer liquid-phase epitaxy (LbL-LPE) approach selectively yields amorphous films, face-on (001)-oriented films, or nearly edge-on (100)-oriented structures by tuning the synthesis conditions [1]. The effectiveness and reproducibility of the method are confirmed by quantitative analysis of synchrotron GIWAXS data across multiple samples, using the degree of orientation (DO) and the Hermans orientation parameter (HOP) extracted from the azimuthal intensity distribution of the (001) reflection. Mapping DO and HOP as a function of synthesis conditions, number of growth cycles, and different interface chemistry (16-mercaptohexadecanoic acid or (4-(4-pyridyl)phenyl)methanethiol self-assembled monolayer) allowed us to identify fabrication regime that supports near-single-crystal growth.
Beyond this system, the proposed analysis offers a streamlined GIWAXS workflow for evaluating qz reflections when pole figures down to γ = 0° are not accessible. This enables reliable comparison between datasets, robust assessment of synthesis reproducibility, and direct extension to related oriented MOF film systems.
[1] E. Afanasenko et al., arXiv:2603.24320, 2026. DOI: 10.48550/arXiv.2603.24320