scholarly journals Ultrafast spin-state photoswitching in a crystal and slower consecutive processes investigated by femtosecond optical spectroscopy and picosecond X-ray diffraction

2012 ◽  
Vol 14 (18) ◽  
pp. 6192 ◽  
Author(s):  
Eric Collet ◽  
Nicolas Moisan ◽  
Chérif Baldé ◽  
Roman Bertoni ◽  
Elzbieta Trzop ◽  
...  
Keyword(s):  
Optical Spectroscopy ◽  
Spin State ◽  
X Ray Diffraction ◽  
X Ray ◽  
Femtosecond Optical Spectroscopy

scholarly journals Spin State Behavior of A Spin-Crossover Iron(II) Complex with N,N′-Disubstituted 2,6-bis(pyrazol-3-yl)pyridine: A Combined Study by X-ray Diffraction and NMR Spectroscopy

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 793
Author(s):  
Elizaveta K. Melnikova ◽  
Dmitry Yu. Aleshin ◽  
Igor A. Nikovskiy ◽  
Gleb L. Denisov ◽  
Yulia V. Nelyubina
Keyword(s):  
Nmr Spectroscopy ◽  
Spin State ◽  
Metal Ion ◽  
Spin Crossover ◽  
Molecular Design ◽  
Chemical Shifts ◽  
Variable Temperature ◽  
High Spin State ◽  
X Ray Diffraction ◽  
X Ray

A series of three different solvatomorphs of a new iron(II) complex with N,N′-disubstituted 2,6-bis(pyrazol-3-yl)pyridine, including those with the same lattice solvent, has been identified by X-ray diffraction under the same crystallization conditions with the metal ion trapped in the different spin states. A thermally induced switching between them, however, occurs in a solution, as unambiguously confirmed by the Evans technique and an analysis of paramagnetic chemical shifts, both based on variable-temperature NMR spectroscopy. The observed stabilization of the high-spin state by an electron-donating substituent contributes to the controversial results for the iron(II) complexes of 2,6-bis(pyrazol-3-yl)pyridines, preventing ‘molecular’ design of their spin-crossover activity; the synthesized complex being only the fourth of the spin-crossover (SCO)-active kind with an N,N′-disubstituted ligand.

scholarly journals Characterization of Pr-Doped LaF3 Nanoparticles Synthesized by Different Variations of Coprecipitation Method

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
M. S. Pudovkin ◽  
D. A. Koryakovtseva ◽  
E. V. Lukinova ◽  
S. L. Korableva ◽  
R. Sh. Khusnutdinova ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Optical Spectroscopy ◽  
Coprecipitation Method ◽  
Luminescence Lifetime ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Hall Method ◽  
Stoichiometric Proportion

A set of Pr3+:LaF3 nanoparticles (NPs) were synthesized via coprecipitation method at three stoichiometric proportions of La(NO3)3, Pr(NO3)3, and NaF (1 : 0.8, 1 : 1, and 1 : 6, respectively). Two ways of mixing of the La(NO3)3, Pr(NO3)3, and NaF solutions (dropwise and swift addition) were used. One sample was subjected to microwave (MW) treatment for 30, 90, and 180 min. All the samples were characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). For all the samples, optical spectroscopy experiments were carried out. The XRD data were analyzed via the Debye-Scherrer and Williamson-Hall methods. It was revealed that the way of mixing of the La(NO3)3, Pr(NO3)3, and NaF solutions strongly affects the shape of the NPs. The slow dropwise addition of the NaF solution leads to the plate-like NP (PLNP) formation; otherwise, the swift addition of the NaF solution leads to the formation of more sphere-like NPs (SLNPs). The size and regularity in shape of the NP increase with the increasing stoichiometric proportion of La(NO3)3, Pr(NO3)3, and NaF from 1 : 0.8 to 1 : 6. The size and regularity in shape of the SLNPs increase with the increasing time of MW treatment. The Debye-Scherrer and Williamson-Hall methods confirmed the anisotropic shape of the PLNPs. The Williamson-Hall method showed that the values of strain are almost similar for all the samples (around 14∗10-4). Optical spectroscopy experiments revealed that although all the samples have an equal chemical composition, the luminescence lifetimes for different samples differ between each other. The luminescence lifetime of the PLNPs is less than that of the SLNPs having an equal stoichiometric proportion of La(NO3)3, Pr(NO3)3, and NaF. The luminescence lifetime of the 1 : 1 SLNPs increases with the increasing time of MW treatment.

The effect of the 3-trifluoromethyl substituent in polypyrazolylborato complexes on the iron(II) spin state; X-ray diffraction and absorption and Mössbauer studies

2001 ◽  
Vol 318 (1-2) ◽  
pp. 67-76 ◽  
Author(s):  
P Cecchi ◽  
M Berrettoni ◽  
M Giorgetti ◽  
G Gioia Lobbia ◽  
S Calogero ◽  
...  
Keyword(s):  
Spin State ◽  
X Ray Diffraction ◽  
Mössbauer Studies ◽  
X Ray

Complex Defects in Lanthanide ion-Exchanged Beta Aluminas

1988 ◽  
Vol 135 ◽  
Author(s):  
Pedro Valergai ◽  
Xianglin Jin ◽  
Frank Vozzo ◽  
Walter L. Roth
Keyword(s):  
Optical Spectroscopy ◽  
Unit Cell ◽  
Lanthanide Ions ◽  
Extended Defects ◽  
Sodium Ions ◽  
X Ray Diffraction ◽  
Lanthanide Ion ◽  
X Ray ◽  
Beta Alumina

AbstractNa+ beta alumina crystals, ion-exchanged with Eu2+ and Nd3+, were studied using x-ray diffraction and optical spectroscopy. In partially-exchanged crystals, we found different concentrations of sodium and lanthanide ions in the two conduction planes of the unit cell. The results suggest that pairs of sodium ions are rapidly replaced by lanthanide ions in regions of the planes bridged by VAl-Ali-O-Ali-VAl extended defects.

scholarly journals High pressure behavior of Ga-doped LaMnO3: a combined X-ray diffraction and optical spectroscopy study

2010 ◽  
Vol 20 (7) ◽  
pp. 1304-1311 ◽  
Author(s):  
Lorenzo Malavasi ◽  
Maria Baldini ◽  
Daniele di Castro ◽  
Alessandro Nucara ◽  
Wilson Crichton ◽  
...  
Keyword(s):  
High Pressure ◽  
Optical Spectroscopy ◽  
Spectroscopy Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pressure Behavior

A combined diffraction and EXAFS study of LaCoO3 and La0.5Sr0.5Co0.75Nb0.25O3 powders

2017 ◽  
Vol 32 (S1) ◽  
pp. S52-S55
Author(s):  
E. A. Efimova ◽  
V. V. Sikolenko ◽  
D. V. Karpinsky ◽  
I. O. Troyanchuk ◽  
S. Pascarelli ◽  
...  
Keyword(s):  
Spin State ◽  
State Transition ◽  
X Ray Diffraction ◽  
Absorption Data ◽  
X Ray ◽  
Bond Lengths ◽  
Structural Distortions ◽  
Spin State Transition ◽  
Local Range ◽  
X Ray Absorption

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.

Preparation of Quantum-Sized Semiconductor Sulfide-Doped Gels

1992 ◽  
Vol 272 ◽  
Author(s):  
T. Gacoin ◽  
J.P. Boilot ◽  
F. Chaput ◽  
A. Lecomte
Keyword(s):  
Optical Spectroscopy ◽  
Small Angle ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Direct Precipitation ◽  
Semiconductor Particles ◽  
Optically Transparent ◽  
Thiolate Complexes

ABSTRACTUltrasmall semiconductor particles (CdS, ZnS and PbS) are produced either by direct precipitation, γ-radiolysis or in mimetic membranes. A pure cluster powder is then prepared from a chemical capping reaction. The capping of the cluster surface by thiolate complexes permits the separation of aggregates without fusion. These capped clusters can be dispersed in different solvents such as sol-gel precursors allowing to prepare dense and optically transparent xerogels with semiconductor clusters grafted on oxide polymers. The nanocrystallites are characterized by X-ray diffraction, small-angle X-ray scattering and optical spectroscopy.

InAs/GaSb superlattices characterized by high-resolution x-ray diffraction and infrared optical spectroscopy

1995 ◽  
Author(s):  
Frank Fuchs ◽  
N. Herres ◽  
J. Schmitz ◽  
K. M. Pavlov ◽  
Joachim Wagner ◽  
...  
Keyword(s):  
High Resolution ◽  
Optical Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Thermal trapped iron(II) high spin state investigated by X-ray diffraction

2004 ◽  
Vol 65 (1) ◽  
pp. 17-23 ◽  
Author(s):  
M. Marchivie ◽  
P. Guionneau ◽  
J.F. Létard ◽  
D. Chasseau ◽  
J.A.K. Howard
Keyword(s):  
High Spin ◽  
Spin State ◽  
High Spin State ◽  
X Ray Diffraction ◽  
X Ray

On the Crystal Structure and Optical Spectroscopy of Rare Earth Comprising Quaternary Tungstates Li3Ba2RE3(WO4)8 (RE = La-Nd, Sm-Ho)

2021 ◽  
Author(s):  
Jan-Niklas Keil ◽  
Christian Paulsen ◽  
Florian Rosner ◽  
Rainer Pöttgen ◽  
Thomas Jüstel
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Single Crystal ◽  
Optical Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Synthesis Route ◽  
Ceramic Synthesis

The quaternary tungstates Li3Ba2RE3(WO4)8 (RE = La-Nd, Sm-Ho) were obtained by a ceramic synthesis route and were characterized by powder and single crystal X-ray diffraction. The structures of Li3Ba2Pr3(WO4)8 and Li3Ba2Tb3(WO4)8 were...

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