Atomic structure - X-ray analysis.

X-ray peak broadening analysis in LaMnO3+δ nano-particles with rhombohedral crystal structure

In this work, structural and magnetic properties of LaMnO3+δ compound prepared by citrate precursor method and annealed in presence of oxygen are investigated. The structural characterization of LaMnO3+δ by X-ray powder diffraction and using X’pert package and Fullprof program is evidence for a rhombohedral structure (R-3c space group) confirmed by FTIR measurement. The magnetic measurements sh...

Band structure and atomic sum rules for x - ray dichroism

– Corrections to the atomic orbital sum rule for circular magnetic x-ray dichroism in solids are derived using orthonormal LMTOs as a single-particle basis for electron band states. Atomic physics affords a theory of x-ray dichroism by providing a set of sum rules which relate dichroic intensities, integrated over a finite energy interval, to the ground-state expectation value of effective one-...

Projections of local atomic structure revealed by wavelet analysis of x-ray absorption anisotropy

We propose and verify in an experiment a wavelet transform approach for analysis of x-ray absorption anisotropy XAA patterns recorded using a broadband polychromatic x-ray beam. XAA results from the interference between an incident plane wave with spherical waves scattered from atoms inside the sample. This interference modifies the total x-ray field amplitude at the sites of absorbing atoms an...

Structure of nanocrystalline MgFe2O4 from X-ray diffraction, Rietveld and atomic pair distribution function analysis

Confirmation of disordered structure of ultrasmall CdSe nanoparticles from X-ray atomic pair distribution function analysis.

The atomic pair distribution function (PDF) analysis of X-ray powder diffraction data has been used to study the structure of small and ultra-small CdSe nanoparticles. A method is described that uses a wurtzite and zinc-blende mixed phase model to account for stacking faults in CdSe particles. The mixed-phase model successfully describes the structure of nanoparticles larger than 2 nm yielding ...