Extended X-ray absorption fine structure studies of magnetic nanoparticles

2011 ◽  
Vol 1 (SRMS-7) ◽  
Author(s):  
A. Agarwal ◽  
M. K. Singh ◽  
T. Kaneko ◽  
S.-I. Nagamatsu ◽  
T. Konishi ◽  
...  

We have synthesized nickel by means of pulsed laser ablation. A nickel disc was used for ablation with the focused output of fundamental harmonic from Nd:YAG laser. X-ray diffraction result shows that the synthesized nanoparticles are of pure metallic nickel with a face-centred cubic structure and the average particle size is 35 nm. The extended X-ray absorption fine structure (EXAFS) studies of pure nickel foil and the synthesized nanoparticles show similar structures. The position of the main peak is same in these nanoparticles with reference to the nickel foil. The only difference was observed in the reduction of the amplitude. The nearest-neighbour distance is similar as for pure nickel foil. The Debye–Waller factor is also similar. There is no trace of oxide and hydroxide in the EXAFS data, suggesting that the synthesized nanoparticles contain only nickel metal.

2000 ◽  
Vol 454-456 ◽  
pp. 723-728 ◽  
Author(s):  
H. Magnan ◽  
P. Le Fèvre ◽  
A. Midoir ◽  
D. Chandesris ◽  
H. Jaffrès ◽  
...  

Author(s):  
Kazumasa Murata ◽  
Junya Ohyama ◽  
Atsushi Satsuma

In the present study, the redispersion behavior of Ag particles on ZSM-5 in the presence of coke was observed using in situ X-ray absorption fine structure (XAFS) spectroscopy.


2021 ◽  
Author(s):  
Gregory M. Su ◽  
Han Wang ◽  
Brandon R. Barnett ◽  
Jeffrey R. Long ◽  
David Prendergast ◽  
...  

In situ near edge X-ray absorption fine structure spectroscopy directly probes unoccupied states associated with backbonding interactions between the open metal site in a metal–organic framework and various small molecule guests.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Hiroyuki Ikemoto ◽  
Takafumi Miyanaga

AbstractIn this review, we make a survey of the structure studies for the chalcogen elements and several chalcogenides in liquid, amorphous and nanosized state by using X-ray absorption fine structure (XAFS). The chalcogen elements have hierarchic structures; the chain structure constructed with the strong covalent bond as a primary structure, and the weaker interaction between chains as a secondary one. Existence of these two kinds of interactions induces exotic behaviors in the liquid, amorphous and nanosized state of the chalcogen and chalcogenides. XAFS is a powerful structure analysis technique for multi-element systems and the disordered materials, so it is suitable for the study of such as liquid, amorphous and nanosized mixtures. In section 2, the structures for the liquid state are discussed, which show the interesting semiconductor-metal transition depending on their temperatures and components. In section 3, the structure for the amorphous states are discussed. Especially, some of chalcogens and chalcogenides present the photostructural change, which is important industrial application. In section 4, the structures of nanosized state, nanoparticles and isolated chain confined into the narrow channel, are discussed. The studies of the nanoparticle and the isolated chain reveal the alternative role between the intrachain covalent bonds and the interchain interaction.


Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1315
Author(s):  
Takafumi Miyanaga

X-ray absorption fine structure (XAFS) is a powerful technique used to analyze a local electronic structure, local atomic structure, and structural dynamics. In this review, I present examples of XAFS that apply to the local structure and dynamics of functional materials: (1) structure phase transition in perovskite PbTiO3 and magnetic FeRhPd alloys; (2) nano-scaled fluctuations related to their magnetic properties in Ni–Mn alloys and Fe/Cr thin films; and (3) the Debye–Waller factors related to the chemical reactivity for catalysis in polyanions and ligand exchange reaction. This study shows that the local structure and dynamics are related to the characteristic function of the materials.


2003 ◽  
Vol 107 (46) ◽  
pp. 12562-12565 ◽  
Author(s):  
Shuji Matsuo ◽  
Ponnusamy Nachimuthu ◽  
Dennis W. Lindle ◽  
Hisanobu Wakita ◽  
Rupert C. C. Perera

Sign in / Sign up

Export Citation Format

Share Document