Due to their limited length of structural coherence nanocrystalline materials show very diffuse powder X-ray diffraction patterns that are difficult to interpret unambiguously. We demonstrate that a combination of high-energy X-ray powder diffraction and atomic pair distribution function analysis can be used to both assess the geometry (i.e., size and shape) and determine the internal atomic or...

Electron paramagnetic resonance ~EPR!, Raman scattering, and neutronand x-ray-diffraction experiments were performed in polycrystalline samples of La2Ni0.5Li0.5O4 as a function of temperature. Structural studies confirm a partial cation ordering of Ni and Li at the metal sites. As the temperature decreases, EPR measurements show an increasing g-value anisotropy (g'2g i) and neutron and x-ray-di...

The use of softer-energy X-rays produced by synchrotron radiation for diffraction is an area of current interest. In this paper, experiments exploiting resonant scattering at the L absorption edges of 3d transition metal elements are reported. Such energies, typically 500-1000 eV, are at the extreme limit of soft X-ray diffraction where absorption effects are so severe that the sample and diffr...

Pure and doped magnesium oxide nanoparticles were successfully synthesized employing a sol-gel process. The synthesized nanoparticles were characterized by thermal differential analysis, X-ray powder diffraction, transmission electron microscopy, scanning electron microscope, energy-dispersive X-ray spectroscopy, and vibrating sample magnetometer. X-ray diffraction patterns confirmed the crysta...

A technique based on x-ray diffraction (XRD) is introduced to understand the variation of the grain-to-grain ordering in FePt recording media. We classify the possible ways that the grains may be ordered into three types: homogeneous ordering, inhomogeneous ordering, and bipolar ordering. We study the possible impact of each type of ordering on the XRD spectra in terms of the relative angular p...

Temperature-dependent dc susceptibility and x-ray powder diffraction on a pure tetragonal sample of Sr(2)VO(4) show an antiferromagnetic orbital-ordering transition at T(oo) = 97 K, in which the occupied orbitals lie along the c axis. The unusual broadening of the x-ray Bragg peaks throughout the orbital-ordering transition temperature region indicates that this process occurs in stages, and th...