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Title: First glimpse of the soft x-ray induced excited spin-state trapping effect dynamics on spin cross-over molecules

The dynamics of the soft x-ray induced excited spin state trapping (SOXIESST) effect of Fe(phen){sub 2}(NCS){sub 2} (Fe-phen) powder have been investigated by x-ray absorption spectroscopy (XAS) using the total electron yield method, in a wide temperature range. The low-spin (LS) state is excited into the metastable high-spin (HS) state at a rate that depends on the intensity of the x-ray illumination it receives, and both the temperature and the intensity of the x-ray illumination will affect the maximum HS proportion that is reached. We find that the SOXIESST HS spin state transforms back to the LS state at a rate that is similar to that found for the light induced excited spin state trapping (LIESST) effect. We show that it is possible to use the SOXIESST effect in combination with the LIESST effect to investigate the influence of cooperative behavior on the dynamics of both effects. To investigate the impact of molecular cooperativity, we compare our results on Fe-phen with those obtained for Fe([Me{sub 2}Pyrz]{sub 3}BH){sub 2} (Fe-pyrz) powder, which exhibits a similar thermal transition temperature but with a hysteresis. We find that, while the time constant of the dynamic is identical for both molecules, the SOXIESST effect ismore » less efficient at exciting the HS state in Fe-pyrz than in Fe-phen.« less
Authors:
;  [1] ;  [2] ;  [3] ; ; ; ; ; ;  [1] ; ; ;  [4] ; ;  [5] ;  [6]
  1. Institut de Physique et de Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS UMR 7504 23 rue du Loess, 67034 Strasbourg (France)
  2. (Germany)
  3. Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwashi, Chiba 277-8581 (Japan)
  4. Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP48, 91192 Gif-sur-Yvette (France)
  5. Institut of Molecular Science, Universitat de València, Edifici de Instituts de Paterna, Apartat de Correus 22085, 46071 València (Spain)
  6. Physikalisches Institut, Karlsruhe Institut of Technology, Wolfgang-Gaede-Str. 1, 76131 Karlsruhe (Germany)
Publication Date:
OSTI Identifier:
22220481
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 139; Journal Issue: 7; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 74 ATOMIC AND MOLECULAR PHYSICS; 36 MATERIALS SCIENCE; 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; ABSORPTION SPECTROSCOPY; EXCITED STATES; HYSTERESIS; SOFT X RADIATION; SPIN; TRANSITION TEMPERATURE; TRAPPING; X-RAY SPECTROSCOPY