First principles calculation of a large variation in dielectric tensor through the spin crossover in the CsFe[Cr(CN){sub 6}] Prussian blue analogue

Journal Article · Mon Apr 14 04:00:00 EDT 2014 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4869864· OSTI ID:22253284

The dielectric response of spin-crossover (SCO) materials is a key property facilitating their use in next-generation information processing technologies. Solid state hybrid density functional theory calculations show that the temperature-induced and strongly hysteretic SCO transition in the Cs{sup +}Fe{sup 2+}[Cr{sup 3+}(CN{sup −}){sub 6}] Prussian blue analogue (PBA) is associated with a large change (Δ) in both the static, Δε{sup 0}(HS − LS), and high frequency, Δε{sup ∞}(HS − LS) dielectric constants. The SCO-induced variation in CsFe[Cr(CN){sub 6}] is significantly greater than the experimental Δε values observed previously in other SCO materials. The phonon contribution, Δε{sup phon}(HS − LS), determined within a lattice dynamics approach, dominates over the clamped nuclei term, Δε{sup ∞}(HS − LS), and is in turn dominated by the low-frequency translational motions of Cs{sup +} cations within the cubic voids of the Fe[Cr(CN){sub 6}]{sup −} framework. The Cs{sup +} translational modes couple strongly to the large unit cell volume change occurring through the SCO transition. PBAs and associated metal-organic frameworks emerge as a potentially fruitful class of materials in which to search for SCO transitions associated with large changes in dielectric response and other macroscopic properties.

• OSTI ID: 22253284
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 14 Vol. 140; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
CATIONS
CESIUM IONS
CHROMIUM IONS
DENSITY FUNCTIONAL METHOD
DIELECTRIC MATERIALS
DIELECTRIC TENSOR
FERROCYANIDES
IRON IONS
ORGANOMETALLIC COMPOUNDS
PERMITTIVITY
SOLIDS