Abstract
This work investigates the X-ray scattering signatures of disorder in the zeolitic imidazolate framework ZIF-8. Two layer disorder models are examined in reciprocal space and compared with conventional Rietveld analysis. Stacking faults along the [001] direction of the cubic lattice are in poor agreement with experimental powder diffraction data, consistent with previously reported density functional theory studies showing that these defects are energetically unfavorable compared with amorphization. Meanwhile, fluctuation of layer position along the [110] direction of the cubic lattice shows a significant agreement with experimental data. This result is interpreted analogously to an anisotropic strain mechanism, suggesting links between elastic anisotropy and crystallographic imperfections found in metal-organic framework materials. In direct space, it is demonstrated that models accounting for the static position disorder amongst the linker and metal sublattices are required to fit the experimental pair distribution function data.
Original language | English |
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Pages (from-to) | 759-767 |
Number of pages | 9 |
Journal | Journal of Applied Crystallography |
Volume | 54 |
DOIs | |
State | Published - Jun 1 2021 |
Funding
Structure refinement and interpretation was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences Early Career Research Program Award KC040602, under contract No. DE-AC05-00OR22725. Sample preparation, data collection and interpretation was supported as part of UNCAGE-ME, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science (Basic Energy Sciences), under award No. DESC0012577. PCM and MRR acknowledge the US Department of Energy Office of Science (Basic Energy Sciences) for research funding. MRR also acknowledges the National Energy Research Scientific Computing Center (NERSC), a US Department of Energy (DOE) Office of Science User Facility, operated under contract No. DE-AC02-05CH11231, for access to supercomputing resources. This research used resources of the Advanced Photon Source, a US Department of Energy Office of Science User Facility operated by Argonne National Laboratory under contract No. DE-AC02-06CH11357.
Keywords
- defects
- metal-organic frameworks
- pair distribution function
- total scattering
- zeolitic imidazolate framework