Examples of PDF analysis on crystalline materials by high resolution pulsed neutron diffraction

Kodama, Katsuaki

no journal, , 

We introduced the following recent studies by means of atomic pair distribution (PDF) analysis. (1) For the multiferroic material BiMnO, we determine the structural parameters and the sizes of the domains with lower symmetries and discuss the symmetry of bulk materials. (2) We discover the local symmetry breaking of the cubic symmetry in MnCuGeN with a giant negative thermal expansion. Due to the local symmetry breaking, we can also detect the hyperfine field at N-site from the ordered magnetic moment by NMR and determine the temperature dependence of the ordered moment in the temperature region where the negative thermal expansion is observed. (3) We determine the composition and structure of Mn-oxide nanoparticle which adsorb the gold in a seawater. (4) We give the exact formulation of PDF analysis including the damping effect induced by the finite size of a nanoparticle. It is confirmed that our formulation can reproduce observed PDF of the nanoparticle, by the measurement on TiO nanoparticle.