Subtle structural features such as disorder and anharmonic motion may be accurately characterized from nuclear density distributions (NDDs). As a viable alternative to neutron diffraction, this paper introduces a new approach named the nuclear-weighted X-ray maximum entropy method (NXMEM) for reconstructing pseudo NDDs. It calculates an electron-weighted nuclear density distribution (eNDD), exp...

Neutron diffraction has been used for engineering applications for nearly three decades. The basis of the technique is powder diffraction following Bragg’s Law. The measured diffraction patterns provide information about internal strains, texture and microstructure, which can be deduced from the peak positions, peak intensities, and peak widths, respectively. Most structural materials are aniso...

High real-space-resolution atomic pair distribution functions of La12xCaxMnO3 (x50.12, 0.25, and 0.33! have been measured using high-energy x-ray powder diffraction to study the size and shape of the MnO6 octahedron as a function of temperature and doping. In the paramagnetic insulating phase we find evidence for three distinct bond lengths which we ascribe to Mn-O, Mn-O-short, and Mn-O-long bo...

Recent advances in crystallographic computing and availability of high-resolution diffraction data have made it relatively easy to solve crystal structures from powders that would have traditionally required single crystal samples. The success of direct space methods depends heavily on starting with an accurate molecular model. In this paper we address the applicability of using these methods i...

X-ray powder diffraction assumes many roles in the analysis of pharmaceuticals. Pharmaceuticals, typically organic solids, exist in numerous solid forms that feature different physical and chemical properties. The vast majority of pharmaceuticals are administered as oral tablet dosage forms. In order for a drug molecule to be absorbed by the body, it must first dissolve. One of the most effecti...

The material design with controlled structure was performed on titanium monoxide with structural vacancies on both sublattices. The polycrystalline powder of disordered titanium monoxide TiO0.98 with B1 structure was subjected to high pressures up to 60 kbar and high temperatures up to 2273 K. The X-ray powder diffraction of as-prepared and treated powders revealed cubic singlephase crystals. T...

Nanocrystalline yttrium orthovanadate (YVO4): Eu powders with different morphologies were synthesized in basic media by surfactant-assisted hydrothermal process. The structures and optical properties of products were investigated using the X-ray powder diffraction, transmission electron microscopy, and photoluminescence spectroscopy. Results showed that pH value played a key role in the formati...

The Physicochemical characteristics of several kinds of toothpaste and natural powder samples and their antibacterial activity against Viridans streptococci bacteria have been studied in vitro. The Physicochemical analysis such as pH, conductivity, and moisture and fluoride concentration of the toothpaste and natural powder along with X-Ray Diffraction made in the consideration to indicating th...

Stoichiometric RMnO3 perovskites have been prepared in the widest range of R3+ ionic sizes, from PrMnO3 to ErMnO3. Soft-chemistry procedures have been employed; inert-atmosphere annealings were required to synthesize the materials with more basic R cations (R = Pr, Nd), in order to minimize the unwanted presence of Mn4+. On the contrary, annealings in O2 flow were necessary to stabilize the per...

A neutron diffraction method applicable to nonlamellar phases of substrate-supported lipid membranes is described and validated. When prepared on a flat substrate, the resulting nonlamellar phases have layered symmetry which provides some advantages over powder diffraction for detailed structure determination. This approach recently led to the detection of a rhombohedral phase and a distorted h...