Photoinduced charge-transfer process in rubidium manganese hexacyanoferrate probed by Raman spectroscopy

Journal Article · Wed Oct 21 00:00:00 EDT 2009 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.3245863· OSTI ID:21559795

Fukaya, R; Nakajima, M; Suemoto, T ^[1]; Tokoro, H; Ohkoshi, S ^[2]

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1. Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan)
2. Department of Chemistry, School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

The photoinduced charge-transfer process in Rb{sub 0.94}Mn[Fe(CN){sub 6}]{sub 0.98}{center_dot}0.2H{sub 2}O is investigated by observing the valence states of the metal ions by Raman spectroscopy. The sample in the high-temperature phase is irradiated at the ligand to metal, CN{sup -}{yields}Fe(III) and charge-transfer band ({lambda}=395 nm). The Fe(III)-CN-Mn(II) pair valence state corresponding to the high-temperature configuration is totally depleted after prolonged irradiation, and the Fe(II)-CN-Mn(III) pair valence state corresponding to the low-temperature configuration appears. In addition, two kinds of CN stretching modes, ascribed to Fe(II)-CN-Mn(II) and Fe(III)-CN-Mn(III) pair valence states, are found. The photoproduction process of each pair valence states is well reproduced by a kinetic model assuming a charge transfer from Mn(II) to Fe(III). During irradiation, continuous shifts of the Raman peaks are found and ascribed to a release of the strain due to the lattice mismatching between the high-temperature and the photoinduced phases. This behavior indicates that the photoinduced phase created locally in the high-temperature-phase lattice grows up to a photoinduced phase domain. The conversion efficiency is lowered with decreasing temperature, indicating the existence of an energy barrier. We propose a model, which can explain the existence of an energy barrier in the electronic excited state.

• OSTI ID: 21559795
• Journal Information: Journal of Chemical Physics, Vol. 131, Issue 15; Other Information: DOI: 10.1063/1.3245863; (c) 2009 American Institute of Physics; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CONFIGURATION
CRYSTAL DEFECTS
CYANIDES
EFFICIENCY
EXCITED STATES
FERRATES
IRRADIATION
LIGANDS
MANGANESE
MANGANESE COMPOUNDS
PEAKS
PHASE TRANSFORMATIONS
PHOTOPRODUCTION
RAMAN SPECTRA
RAMAN SPECTROSCOPY
RUBIDIUM
RUBIDIUM COMPOUNDS
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0400-1000 K
VALENCE
ALKALI METAL COMPOUNDS
ALKALI METALS
BASIC INTERACTIONS
CRYSTAL STRUCTURE
ELECTROMAGNETIC INTERACTIONS
ELEMENTS
ENERGY LEVELS
INTERACTIONS
IRON COMPOUNDS
LASER SPECTROSCOPY
METALS
OXYGEN COMPOUNDS
PARTICLE INTERACTIONS
PARTICLE PRODUCTION
SPECTRA
SPECTROSCOPY
TEMPERATURE RANGE
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS