High real-space resolution structure of materials by high-energy x-ray diffraction

Abstract

Results of high-energy synchrotron radiation experiments are presented demonstrating the advantages of the high-resolution atomic Pair Distribution Function technique in determining the structure of materials with intrinsic disorder.

Unveiling Nanoscale Compositional and Structural Heterogeneities of Highly Textured Mg0.7Ti0.3Hy Thin Films

“…These are smaller than the lattice parameters of Mg ( a = b = 3.2085 Å and c = 5.2106 Å) but larger than those of Ti ( a = b = 2.95111 Å and c = 4.68433 Å). , Interestingly, these values are rather close to the calculated values for a Mg 0.7 Ti 0.3 solid solution alloy ( a = b = 3.1313 Å and c = 5.0527 Å) using Vegard’s law . This good fit is obtained at the expense of a large isotropic atomic displacement parameter ( U iso = 0.041(7) Å 2 ), indicating the presence of large random displacement in the sample . We also tried two-phase modeling using a nanosized hcp Ti model and an hcp Mg model.…”

“…40 This good fit is obtained at the expense of a large isotropic atomic displacement parameter (U iso = 0.041(7) Å 2 ), indicating the presence of large random displacement in the sample. 41 We also tried two-phase modeling using a nanosized hcp Ti model and an hcp Mg model. However, the fit did not improve despite a greater number of parameters being used.…”

Hierarchical Materials as Tailored Nuclear Waste Forms: A Perspective

“…Subtle material characteristics at the nanometer and smaller length scales have been characterized using the PDF method, for example, nanodomains in relaxor ferroelectrics, where multication oxides show extensive clustering of cations. Similar or even greater chemical complexity is common in alloy systems, and therefore we anticipate that application of the PDF analysis tool to complex alloy nanoparticles , will allow a more complete description of the interatomic bonding and local environments that lead to, for example, improved resistance to leaching.…”

Total Scattering Study of Local Structural Changes in MnAs1–xPx Influenced by Magnetic Interactions

“…When different sized atoms are substituted in the same crystal lattice, it is expected to have different bond distances. For example, in the case of Ga 1– x In x As, high-resolution PDF data clearly shows two very distinctive peaks corresponding to In–As and Ga–As at 2.65 and 2.45 Å, respectively . Two Gaussian peaks were used to fit these peaks to find out the corresponding bond distances.…”

“…For example, in the case of Ga 1−x In x As, highresolution PDF data clearly shows two very distinctive peaks corresponding to In−As and Ga−As at 2.65 and 2.45 Å, respectively. 26 Two Gaussian peaks were used to fit these peaks to find out the corresponding bond distances. Two peaks were clearly resolved because of the data (Q max = 45 Å −1 ).…”