Study of charge density and crystal structure of (La0.75Sr0.25)MnO3.00 and (Ba0.5Sr0.5)(Co0.8Fe0.2)O2.33−δ at 500–900K by in situ synchrotron X-ray diffraction

Using in situ X-ray absorption spectroscopy to study the local structure and oxygen ion conduction mechanism in (La0.6Sr0.4)(Co0.2Fe0.8)O3−δ

“…The estimated values of s 2 were fixed for EXAFS fitting procedure, because the strong correlations are known between N i and s 2 . This may be validated by former studies using the TG, XRD, and neutron diffraction results [7,[19][20][21][22]; the values of N i , i.e., the amount of oxygen vacancy (d) change more readily than s during the reduction. Table 5 shows the examples of the oxygen content (3À d), s 2 , S 0 2 , and the reliability factor (R-factor) estimated by EXAFS analysis.…”

“…We have previously analyzed the oxygen ion electron conduction mechanism with Rietveld refinements and the maximum entropy method, using synchrotron X-ray and neutron diffraction data [20][21][22]. These techniques, however, observed only the average information for the cathode materials and/or B site, and did not identify information regarding each element at the B site.…”

Micro- and macro-indentation behaviour of Ba0.5Sr0.5Co0.8Fe0.2O3−d perovskite

“…It appears that the strong decrease in fracture toughness was coupled to the decrease in elastic modulus and both are related to the inherent bond strength. In two recent studies 16,17 it has been shown that within the temperature range 300-500 K substantial variation in the charge density profile of different A-O and B-O bonds occurred for BSCF and there was a decrease in bond-strength of certain covalent bonds. Since there is no indication of phase change in this temperature range, changes in bond strength due to a distortion of the BO 6 octahedron can be the reason for such simultaneous decrease in elastic modulus and fracture toughness.…”

“…6,7,12 By now also several reports are available on the thermal expansion behaviour and electrical conductivity of BSCF of different compositional variation. [13][14][15] Some recent works 16,17 have reported in great detail the charge density profile, atomic -isotropic displacement parameters and conductivity of BSCF based on data from synchrotron X-ray diffraction measurements, permitting an identification of the detailed temperature dependent oxygen transport mechanisms. Recently, Liu et al 18 have studied the variation of crystal structure and chemical state of BSCF using XRD and X-ray photoelectron spectroscopy (XPS).…”

Oxygen stoichiometry of Ba0.50Sr0.50Co0.80Fe0.20O3−δ obtained by EDTA–citrate method and measured by X-ray and neutron diffraction

“…Itoh et al studied the relationship between oxygen vacancy and ion conductivity showing the importance of the oxygen stoichiometry in these oxides [15].…”