Local Structure and Dynamics in MPt(CN) 6 Prussian Blue Analogues.

Autor: Harbourne EA; Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford OX1 3QR, U.K., Barker H; Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford OX1 3QR, U.K., Guéroult Q; Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford OX1 3QR, U.K., Cattermull J; Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford OX1 3QR, U.K.; Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, U.K., Nagle-Cocco LAV; Cavendish Laboratory, University of Cambridge, JJ Thompson Avenue, Cambridge CB3 0HE, U.K., Roth N; Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford OX1 3QR, U.K., Evans JSO; Department of Chemistry, Durham University, Durham DH1 3LE, U.K., Keen DA; ISIS Facility, Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, U.K., Goodwin AL; Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford OX1 3QR, U.K.
Jazyk: angličtina
Zdroj: Chemistry of materials : a publication of the American Chemical Society [Chem Mater] 2024 May 30; Vol. 36 (11), pp. 5796-5804. Date of Electronic Publication: 2024 May 30 (Print Publication: 2024).
DOI: 10.1021/acs.chemmater.4c01013
Abstrakt: We use a combination of X-ray pair distribution function (PDF) measurements, lattice dynamical calculations, and ab initio density functional theory (DFT) calculations to study the local structure and dynamics in various MPt(CN) 6 Prussian blue analogues. In order to link directly the local distortions captured by the PDF with the lattice dynamics of this family, we develop and apply a new "interaction-space" PDF refinement approach. This approach yields effective harmonic force constants, from which the (experiment-derived) low-energy phonon dispersion relations can be approximated. Calculation of the corresponding Grüneisen parameters allows us to identify the key modes responsible for negative thermal expansion (NTE) as arising from correlated tilts of coordination octahedra. We compare our results against the phonon dispersion relations determined using DFT calculations, which identify the same NTE mechanism.
Competing Interests: The authors declare no competing financial interest.
(© 2024 The Authors. Published by American Chemical Society.)
Databáze: MEDLINE
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