Evidence for surface effects on the intermolecular interactions in Fe(ii) spin crossover coordination polymers

Author(s):  
Thilini K. Ekanayaka ◽  
Hannah Kurz ◽  
Kayleigh A. McElveen ◽  
Guanhua Hao ◽  
Esha Mishra ◽  
...  

From X-ray absorption spectroscopy (XAS) and X-ray photoemission spectroscopy (XPS) it is evident that the spin state transition behavior of Fe(ii) spin crossover coordination polymer crystallites at the surface differs from the bulk.

2021 ◽  
Author(s):  
Thilini K. Ekanayaka ◽  
Hannah Kurz ◽  
Ashley S. Dale ◽  
Guanhua Hao ◽  
Aaron Mosey ◽  
...  

For the spin crossover coordination polymer [Fe(L1)(bipy)]n (where L1 is a N2O22− coordinating Schiff base-like ligand bearing a phenazine fluorophore and bipy = 4,4′-bipyridine), there is compelling additional evidence of a spin state transition.


2006 ◽  
Vol 73 (5) ◽  
Author(s):  
M. Medarde ◽  
C. Dallera ◽  
M. Grioni ◽  
J. Voigt ◽  
A. Podlesnyak ◽  
...  

2012 ◽  
Vol 86 (12) ◽  
Author(s):  
J. Herrero-Martín ◽  
J. L. García-Muñoz ◽  
K. Kvashnina ◽  
E. Gallo ◽  
G. Subías ◽  
...  

2017 ◽  
Vol 32 (S1) ◽  
pp. S52-S55
Author(s):  
E. A. Efimova ◽  
V. V. Sikolenko ◽  
D. V. Karpinsky ◽  
I. O. Troyanchuk ◽  
S. Pascarelli ◽  
...  

A combination of neutron diffraction, synchrotron X-ray diffraction, and high-resolution extended X-ray absorption fine structure measurements has been used to clarify the correlations between long- and local-range structural distortions across the spin-state transition in powders of LaCoO3 and La0.5Sr0.5Co0.75Nb0.25O3. The analysis of the diffraction data has revealed that the isotropic thermal parameters of Co–O bond abnormally increase below 100 K in both samples, while the temperature dependence of the average Co–O bond lengths is linear from 10 to 300 K. We also have found that the Co–O bond lengths are larger in La0.5Sr0.5Co0.75Nb0.25O3, as compared with the ones in LaCoO3. The X-ray absorption data showed an anomalous decrease of the Co–O bond lengths only for LaCoO3, in contrast to the bond length values obtained by diffraction. The structural anomalies observed by spectroscopy measurements are discussed in terms of the spin-state transition model.


2010 ◽  
Vol 163 ◽  
pp. 46-50 ◽  
Author(s):  
Maciej Zubko ◽  
Paweł Zajdel ◽  
Joachim Kusz

We have tested a new method which allows assigning the spin state of the spin crossover (SCO) crystal in-situ during the diffraction experiment. The method is based on the analysis of change of the colour of the SCO compounds. We have found that the off-line setup in transmission geometry is reliable in assigning the magnitude of high spin molecules fraction (γHS) and the character (one step, many steps, histeresis) of the SCO transition. Later on, this method has been used in the in-situ measurements directly on X-ray four-circle diffractometer.


Author(s):  
Guanhua Hao ◽  
Alpha T. N'Diaye ◽  
Thilini K. Ekanayaka ◽  
Ashley S. Dale ◽  
Xuanyuan Jiang ◽  
...  

The X-ray induced spin crossover transition of an Fe(II) molecular thin film in the presence and absence of a magnetic field has been investigated. The thermal activation energy barrier in the soft X-ray activation of the spin crossover transition for [Fe{H2B(pz)2}2(bipy)] molecular thin films is reduced in the presence of an applied magnetic field, as measured through X-ray absorption spectroscopy at various temperatures. The influence of a 1.8 T magnetic field is sufficient to cause deviations from the expected exponential spin state transition behavior that is measured in the field free case. We find that orbital moment diminishes with increasing temperature, relative to the spin moment in the vicinity of room temperature.


2021 ◽  
Vol 7 (10) ◽  
pp. 135
Author(s):  
Guanhua Hao ◽  
Alpha T. N’Diaye ◽  
Thilini K. Ekanayaka ◽  
Ashley S. Dale ◽  
Xuanyuan Jiang ◽  
...  

The X-ray-induced spin crossover transition of an Fe (II) molecular thin film in the presence and absence of a magnetic field has been investigated. The thermal activation energy barrier in the soft X-ray activation of the spin crossover transition for [Fe{H2B(pz)2}2(bipy)] molecular thin films is reduced in the presence of an applied magnetic field, as measured through X-ray absorption spectroscopy at various temperatures. The influence of a 1.8 T magnetic field is sufficient to cause deviations from the expected exponential spin state transition behavior which is measured in the field free case. We find that orbital moment diminishes with increasing temperature, relative to the spin moment in the vicinity of room temperature.


2018 ◽  
Vol 2018 (3-4) ◽  
pp. 385-393 ◽  
Author(s):  
Amine Ould-Hamouda ◽  
Benjamin Viquerat ◽  
Jérôme Degert ◽  
Samir F. Matar ◽  
Jean François Létard ◽  
...  

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