Dynamics of water in prussian blue analogues: Neutron scattering study

Journal Article · Mon Jul 21 04:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4890722· OSTI ID:22308506

Sharma, V. K.; Mitra, S.; Thakur, N.; Yusuf, S. M.; Juranyi, Fanni ^[1]

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1. Laboratory for Neutron Scattering, Paul Scherrer Institut, Villigen (Switzerland)

Dynamics of crystal water in Prussian blue (PB), Fe(III){sub 4}[Fe(II)(CN){sub 6}]{sub 3}.14H{sub 2}O and its analogue Prussian green (PG), ferriferricynaide, Fe(III){sub 4}[Fe(III)(CN){sub 6}]{sub 4}.16H{sub 2}O have been investigated using Quasielastic Neutron Scattering (QENS) technique. PB and its analogue compounds are important materials for their various interesting multifunctional properties. It is known that crystal water plays a crucial role towards the multifunctional properties of Prussian blue analogue compounds. Three structurally distinguishable water molecules: (i) coordinated water molecules at empty nitrogen sites, (ii) non-coordinated water molecules in the spherical cavities, and (iii) at interstitial sites exist in PB. Here spherical cavities are created due to the vacant sites of Fe(CN){sub 6} units. However, PG does not have any such vacant N or Fe(CN){sub 6} units, and only one kind of water molecules, exists only at interstitial sites. QENS experiments have been carried out on both the compounds in the temperature range of 260–360 K to elucidate the dynamical behavior of different kinds of water molecules. Dynamics is found to be much more pronounced in case of PB, compared to PG. A detailed data analysis showed that localized translational diffusion model could describe the observed data for both PB and PG systems. The average diffusion coefficient is found to be much larger in the PB than PG. The obtained domain of dynamics is found to be consistent with the geometry of the structure of the two systems. Combining the data of the two systems, a quantitative estimate of the dynamics, corresponding to the water molecules at different locations is made.

• OSTI ID: 22308506
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 3 Vol. 116; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CARBON NITRIDES
CAVITY RESONATORS
CRYSTALS
CYANIDES
DATA ANALYSIS
DIFFUSION
FERROCYANIDES
IRON COMPLEXES
MOLECULES
NEUTRON DIFFRACTION
NEUTRON REACTIONS
NITROGEN
POTASSIUM COMPOUNDS
QUASI-ELASTIC SCATTERING
TEMPERATURE RANGE 0400-1000 K
WATER