Nanocrystalline EuCrO3 particles (∼25 nm) have been prepared by pre-milling a 1 : 1 molar mixture of Eu2O3 and Cr2O3 for 60 h followed by sintering at 700 °C (12 h). This temperature is ∼500–600 °C lower than those at which the material, in bulk form, is conventionally prepared. Rietveld analysis of the x-ray powder diffraction pattern of the EuCrO3 nanoparticles favours a structural model involving a slight degree of cationic exchange where ∼11% of the Eu3+ and Cr3+ ions exchange their normal dodecahedral A- and octahedral B-sites, respectively, in the perovskite-related structure. This cationic site exchange, which is unusual in a perovskite structure, has been well supported by the corresponding room-temperature 151Eu Mössbauer spectrum of the nanoparticles that in addition to displaying a distribution in the principal component of the EFG tensor (V
zz
) at the usual A-sites of the 151Eu nuclei, also revealed the presence of a subcomponent with ∼11% area fraction and a considerably increased |V
zz
| value that was associated with Eu3+ ions at octahedral B-sites. X-ray photoelectron and Auger electron spectroscopic techniques reveal a complex surface structure where extremely thin layers of un-reacted Eu2O3 and Cr2O3 cover most of the EuCrO3 nanoparticles' surfaces together with some traces of elemental Cr. The binding energies associated with Eu3+ 3d5/2, Eu3+ 4d3/2, Cr3+ 2p3/2 and O2− 1s core-level electrons in EuCrO3 are estimated from the x-ray photoelectron data for the first time.
Articles you may be interested inAn 129I Mössbauer spectroscopic study of iodine doped in poly(vinylpyridines) J. Chem. Phys. 75, 5155 (1981); 10.1063/1.441864 Mössbauer effect of 129I in n-σ and π-σ chargetransfer complexes of iodine in the frozen solution J. Chem. Phys. 72, 6192 (1980); 10.1063/1.439078 129I Mössbauer studies of iodine in the +1 and +3 oxidation states Wl(R) than that taken in Eq. (15) might be Wl(R) =E{b 1 exp[ -0:(R-R...)/R...]-2al(R.../R)7} , and for this choice Eq. (16) is modified by replacing the constant CN by C~3.12e" Ko( 1.0610:),Ko being the modified Bessel function of order 0; for x> 1, Ko(x) =e"'(7r/2x) 1/2 to within 10%.The information concerning the anisotropy is obtained most directly from the amplitude of the oscillatory part of the cross section; in all cases the frequency THE JOURNAL OF CHEMICAL PHYSICS of the oscillations is governed by the rainbow angle of the distorting potential. From Eqs. (11) and (16) we see that the amplitude of the oscillatory contribution is proportional to D (or 1/velocity), or normalized to Ub<.)O) it is proportional to ])3/6. To minimize the contributions from third-and higher-order terms in the cross section, it would be best to extrapolate a plot of the amplitude (normalized to u~(O» versus ])3/6 to ~ the slope of this plot giving the appropriate combination of anisotropy parameters. With the measurements analyzed in this manner, there should be no need to correct the high-energy approximations used in Sees. III and IV to evaluate the various quantities required.The values of isomer shift and quadrupole interaction at the 129 1 nucleus in IBr and ICI complexes with cyclic nitrogen bases have been measured. These have been used to estimate IT and'll" bondings in these complexes. All these complexes exhibit a linear N-I-X (X=CI, Br) linkage. Although the bromine complexes show a systematic dependence of the isomer shift on the basicity of the complexing cyclic amines, no such trend is observed in chlorine complexes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.