			Home About us Contact

Neutron Studies (neutron + studies)

Distribution by Scientific Domains

Chemistry	50%

Selected Abstracts

Neutron Studies of Cation Disorder in Zn2FeV3O11-,.

CHEMINFORM, Issue 46 2004
N. Guskos
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

In Situ Characterization of a Nb and Mo Containing , -TiAl Based Alloy Using Neutron Diffraction and High-Temperature Microscopy,

ADVANCED ENGINEERING MATERIALS, Issue 11 2009
Ian J. Watson
Abstract In recent times, novel titanium aluminides containing the bcc , -phase at high temperatures are being developed for improved hot-working capabilities, however, predictions of the phase diagrams are merely uncertain. Here we present in-situ neutron studies, which are particularly sensitive to the atomic disorder in the ordered phases. Complementary laser scanning confocal microscopy is employed for in-situ microstructural investigations. [source]

Neutron diffraction studies of magnetic and superconducting compounds

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 7 2004
W. B. Yelon
Abstract Neutron diffraction is an extremely valuable tool for the investigation of magnetic and superconducting materials, because of its ability to directly observe periodic magnetic structures, determine magnetic moment directions and magnitudes, to observe light elements that are otherwise difficult to locate from X-ray diffraction due to the strong scattering of heavy elements, or to distinguish nearby elements in the periodic chart. This talk will focus on recent studies of superconducting and magnetic oxides that may provide insight into the interaction of magnetism and superconductivity, and into important changes in other transport properties (colossal magneto-resistance, ionic conductivity, etc.). These materials appear to show promise for a wide range of applications, and the neutron studies may not only help to understand their properties, but may also provide direction for synthesis of compounds that may overcome the limitations of those already discovered. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Bond lengths in organic and metal-organic compounds revisited: X,H bond lengths from neutron diffraction data

ACTA CRYSTALLOGRAPHICA SECTION B, Issue 3 2010
Frank H. Allen
The number of structures in the Cambridge Structural Database (CSD) has increased by an order of magnitude since the preparation of two major compilations of standard bond lengths in mid-1985. It is now of interest to examine whether this huge increase in data availability has implications for the mean bond-length values published in the late 1980s. Those compilations reported mean X,H bond lengths derived from rather sparse information and for rather few chemical environments. During the intervening years, the number of neutron studies has also increased, although only by a factor of around 2.25, permitting a new analysis of X,H bond-length distributions for (a) organic X = C, N, O, B, and (b) a variety of terminal and homometallic bridging transition metal hydrides. New mean values are reported here and are compared with earlier results. These new overall means are also complemented by an analysis of X,H distances at lower temperatures (T, 140,K), which indicates the general level of librational effects in X,H systems. The study also extends the range of chemical environments for which statistically acceptable mean X,H bond lengths can be obtained, although values from individual structures are also collated to further extend the chemical range of this compilation. Updated default `neutron-normalization' distances for use in hydrogen-bond and deformation-density studies are also proposed for C,H, N,H and O,H, and the low-temperature analysis provides specific values for certain chemical environments and hybridization states of X. [source]