Search results for "X-Ray"

Structure, properties and comparison of C,N-chelated and amido-stabilized plumbylenes

2010

The molecular structure of {2-[(CH3)2NCH2]C6H4}2Pb (1) in the solid state was determined by X-ray diffraction techniques on a single crystalline material. Bulky amido ligand stabilized complexes [(i-C3H7)2C6H3]NHLi (2) and [(i-C3H7)2C6H3N(Me3Si)]2Pb (3) were synthesized and characterized both in the solid state and solution by 1H, 13C, 15N and 207Pb NMR and XRD techniques. The structure of both C,N-chelated and bulky amido plumbylenes is compared.

EXAFS study of the local structure of crystalline and nanocrystalline Y2O3using evolutionary algorithm method

2015

Temperature-dependent local structure and lattice dynamics of yttria (Y2O3) were studied by X-ray absorption spectroscopy. Novel method, which combines the reverse Monte Carlo and evolutionary algorithm techniques, was applied for the analysis of extended X-ray absorption fine structure at the Y K-edge. This approach allowed us to reconstruct 3D atomic structure models of crystalline and nanocrystalline Y2O3.

Peculiarities of X-Ray Diffraction in Crystals with Diffuse Boundaries of Twin on System {011}, <011>

2000

X-ray diffraction on (KBr)1−x(KCN)xmixed crystals

1985

Crystallography and Crystal Engineering

2007

Dynamic segregation during ferrite oxidation revealed by XPS

2002

Dynamic segregation phenomena were revealed by XPS during the oxidation of some ferrites (Fe 2.5 Ti 0.5 O 4 , Fe 2.5 Ni 0.5 O 4 , Fe 2 CrO 4 and FeCr 2 O 4 ). This kind of phenomenon induces, at a low temperature (below room temperature), drastic changes in the cationic composition of the most external layers. Dynamic segregation is a function of the cationic composition, the oxidation capability and the morphology of these ferrites. Although dynamic segregation seems to be a quite frequent phenomenon that often can be observed during ferrite oxidation, there are materials in existence where it does not appear, such as molybdenum ferrite.

Amorphous Ge15Te85: density functional, high-energy x-ray and neutron diffraction study

2011

The structure and electronic properties of amorphous Ge15Te85 have been studied by combining density functional (DF) simulations with high-energy x-ray and neutron diffraction measurements. Three models with 560 atoms have been constructed using reverse Monte Carlo methods constrained to (1) agree with the experimental structure factors S(Q), and have (2) energies close to the DF minimum and (3) a semiconducting band structure. The best structure is based on the melt-quenched DF structure and has a small number of Ge–Ge bonds. It shows interlocking networks of Te and GeTe with a significant fraction (22–24%) of voids (cavities). Ge occurs with both tetrahedral and 3 + 3 defective octahedral…

Structural characterization, thermal, dielectric and vibrational properties of tris(allylammonium) hexabromoantimonate(III), (C3H5NH3)3SbBr6

2010

Abstract The novel inorganic–organic hybrid material, allylammonium hexabromoantimonate(III), (C3H5NH3)3SbBr6, has been synthesized and its structure has been determined by means of the single-crystal X-ray diffraction studies at five temperatures (273, 248, 220, 170 and 100 K). At room temperature the compound crystallizes in the monoclinic space group, C2/m. Its crystal structure is composed of the discrete SbBr 6 3 - anions and three non-equivalent allylammonium, (C3H5NH3)+, cations. In (C3H5NH3)3SbBr6 three solid–solid structural phase transitions are detected: a continuous one at 260/256 K (on heating–cooling) from phase I to II, a discontinuous one at 227/208 K (II→III) and another di…

X-ray powder diffraction data for some transition metal phosphites and hypophosphites

1994

A set of nine transition metal oxophosphorous compounds, consisting of four hypophosphites and five phosphites has been synthesized and studied using X-ray powder diffraction techniques. The compounds are α-Mn(H2PO2)2·H2O, Co(H2PO2)2 ·0.53H2O, MCl(H2PO2)2·H2O (M = Co2+, Ni2+), M2(HPO3)2·2H2O (M = Co2+, Ni2+), and M11 (HPO3)8(OH)6 (M = Zn2+, Co2+, Ni2+). Unit cells and X-ray powder patterns are reported.

X-ray powder diffraction study of the stability of solid solutions in (La1−xGdx)OCl

1996

The formation of the solid solutions in the (La1−xGdx)OCl series was studied by X-ray powder diffraction (XPD) at room temperature in the 2θ region between 6.5 and 120°. The Rietveld profile refinement analyses of the XPD patterns were carried out with the background, unit cell, atomic position, isotropic temperature, and Gaussian profile form parameters refined freely. All (La1−xGdx)OCl samples possessed the tetragonal PbFCl-type structure with P4/nmm as the space group (Z=2). The unit cell parameters a and c evolve smoothly through the series and no clustering of the Gd3+ ions was observed according to Vegard's law. The solid solubility exists throughout the whole series. The valence bond…