scholarly journals Magnetic structure of greigite (Fe3S4) probed by neutron powder diffraction and polarized neutron diffraction

2009 ◽  
Vol 114 (B7) ◽  
Author(s):  
Liao Chang ◽  
Brian D. Rainford ◽  
J. Ross Stewart ◽  
Clemens Ritter ◽  
Andrew P. Roberts ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Magnetic Structure ◽  
Powder Diffraction ◽  
Neutron Powder Diffraction ◽  
Polarized Neutron

The magnetic structure of braunite Mn2+Mn3+6O8/SiO4

1998 ◽  
Vol 213 (1) ◽  
Author(s):  
S. Ohmann ◽  
I. Abs-Wurmbach ◽  
N. Stüßer ◽  
T. M. Sabine ◽  
K. Westerholt
Keyword(s):  
Neutron Diffraction ◽  
Magnetic Structure ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Magnetic Moments ◽  
Magnetic Ordering ◽  
Neutron Powder Diffraction ◽  
Powder Diffraction Data ◽  
Neutron Powder Diffraction Data ◽  
Weakly Coupled

AbstractNeutron powder diffraction data of braunite MnThe magnetic structure is dominated by the magnetic ordering of the A layers thus reflecting the relations of the chemical cell: Within the (001) plane of the A sheets magnetic moments of the two nonequivalent MnMagnetization experiments indicate that besides the afordered Mn ions weakly coupled spins ordering at temperatures below 2 K exist. In accordance with that, additional neutron diffraction reflections arise at

Neutron Diffraction Study of the Hexagonal Perovskite-Type Compound LaCrGe3

2012 ◽  
Vol 194 ◽  
pp. 71-74 ◽  
Author(s):  
J.M. Cadogan ◽  
Pierric Lemoine ◽  
Brianna R. Slater ◽  
Arthur Mar ◽  
Maxim Avdeev
Keyword(s):  
Neutron Diffraction ◽  
Diffraction Study ◽  
Magnetic Structure ◽  
Powder Diffraction ◽  
Magnetic Moment ◽  
Neutron Diffraction Study ◽  
Neutron Powder Diffraction ◽  
Type Structure ◽  
Ferromagnetic Structure ◽  
Perovskite Type

The BaNiO3-type structure and the ferromagnetic order (TC = 78 K) of the Cr sublattice in LaCrGe3 have been confirmed by neutron powder diffraction measurements. At 20 K, the magnetic structure is collinear along the c axis with a Cr magnetic moment of 1.24(4) μB. Below 3 K, LaCrGe3 has a spin-canted ferromagnetic structure with a canting angle θ of 32(6) and a Cr magnetic moment of 1.31(4) μB at 1.7 K.

Use of Neutron Diffraction for Describing Texture of Isostatically-Pressed Molybdite Powders

2005 ◽  
Vol 105 ◽  
pp. 83-88 ◽  
Author(s):  
H. Sitepu ◽  
Heinz Günter Brokmeier
Keyword(s):  
Crystal Structure ◽  
Neutron Diffraction ◽  
Powder Diffraction ◽  
Quantitative Description ◽  
Neutron Powder Diffraction ◽  
Powder Diffraction Data ◽  
Neutron Powder Diffraction Data ◽  
Pole Figures ◽  
Diffraction Patterns ◽  
Excellent Tool

The modelling and/or describing of texture (i.e. preferred crystallographic orientation (PO)) is of critical importance in powder diffraction analysis - for structural study and phase composition. In the present study, the GSAS Rietveld refinement with generalized spherical harmonic (GSH) was used for describing isostatically-pressed molybdite powders neutron powder diffraction data collected in the ILL D1A instrument. The results showed that for texture in a single ND data of molybdite the reasonable crystal structure parameters may be obtained when applying corrections to intensities using the GSH description. Furthermore, the WIMV method was used to extract the texture description directly from a simultaneous refinement with 1368 whole neutron diffraction patterns taken from the sample held in a variety of orientations in the ILL D1B texture goniometer. The results provided a quantitative description of the texture refined simultaneously with the crystal structure. Finally, the (002) molybdite pole-figures were measured using the GKSS TEX2 texture goniometer. The results showed that neutron diffraction is an excellent tool to investigate the texture in molybdite.

A Study of the Magnetic Structure of LaMn2O5from Neutron Powder Diffraction Data

2005 ◽  
Vol 2005 (4) ◽  
pp. 685-691 ◽  
Author(s):  
Angel Muñoz ◽  
Jose A. Alonso ◽  
María T. Casais ◽  
María J. Martínez-Lope ◽  
Jose L. Martínez ◽  
...  
Keyword(s):  
Magnetic Structure ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Neutron Powder Diffraction ◽  
Powder Diffraction Data ◽  
Neutron Powder Diffraction Data

Neutron powder diffraction study of the magnetic structure of EuZrO3

2014 ◽  
Vol 26 (9) ◽  
pp. 095401 ◽  
Author(s):  
Maxim Avdeev ◽  
Brendan J Kennedy ◽  
Taras Kolodiazhnyi
Keyword(s):  
Diffraction Study ◽  
Magnetic Structure ◽  
Powder Diffraction ◽  
Neutron Powder Diffraction

scholarly journals Neutron diffraction investigation of the temperature dependence of crystal structure and thermal motions of red HgI2

2007 ◽  
Vol 63 (6) ◽  
pp. 828-835 ◽  
Author(s):  
Dieter Schwarzenbach ◽  
Henrik Birkedal ◽  
Marc Hostettler ◽  
Peter Fischer
Keyword(s):  
Crystal Structure ◽  
Neutron Diffraction ◽  
Powder Diffraction ◽  
Soft Mode ◽  
Layer Structure ◽  
Neutron Powder Diffraction ◽  
Force Constants ◽  
Quantum Oscillator ◽  
Thermal Displacement ◽  
Tetrahedral Layer

The structure of, and anisotropic thermal motions in, the red semiconductor tetrahedral layer structure of HgI2 have been studied with neutron powder diffraction as a function of temperature from 10 to 293 K. Average thermal displacement parameters U eq of the two atoms are comparable in size at 10 K, but U eq(Hg) increases considerably faster with temperature than U eq(I), the Hg—I bond being highly non-rigid. The anisotropic displacement tensor U (I) is strongly anisotropic with one term about twice as large as the others, while U (Hg) is nearly isotropic. All displacement tensor elements, except U 22(I), increase faster with temperature than harmonic quantum oscillator curves indicating a softening of the isolated-atom potentials at large amplitudes. A lattice dynamical model provides arguments that the anisotropic thermal motions of I are dominated by a soft mode with a wavevector at the [½ ½ 0] boundary of the Brillouin zone consisting essentially of coupled librations of the HgI4 tetrahedra, and by translations of the entire layer. The large vibration amplitudes of Hg suggest weak Hg–I force constants compared with the I–I force constants, allowing Hg to move quite freely inside the tetrahedra. The libration mode induces dynamic deformations of the Hg—I bond with twice its frequency. This provides a mechanism for the anharmonicity and may explain the lightening of the color from red to orange upon cooling at ca 80 K.

Measurement of Atomic Elastic Constants by Pulsed Neutron Powder Diffraction

1992 ◽  
Vol 36 ◽  
pp. 577-583
Author(s):  
A. C. Lawson ◽  
G. H. Kwei ◽  
J. A. Goldstone ◽  
B. Cort ◽  
R. I. Sheldon ◽  
...  
Keyword(s):  
High Temperature ◽  
Neutron Diffraction ◽  
Rietveld Refinement ◽  
Powder Diffraction ◽  
Elastic Constants ◽  
Diffraction Data ◽  
High Temperature Superconductors ◽  
Neutron Powder Diffraction ◽  
Neutron Diffraction Data ◽  
Pulsed Neutron

AbstractWe have developed a technique for determining the atomic elastic constants from measurements of the Debye-Waller factors. The Debye-Waller factors are obtained by Rietveld refinement of time-of-flight neutron diffraction data and interpreted in terms of an atomic Debye-Waller temperature. The method is applicable to powders and to materials that must be encapsulated for safety or environmental reasons. We will illustrate our technique with applications to actinide metals, to metallic hydrides and to high-temperature superconductors.

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