Disordered Configuration of Methylammonium of CH_3NH_3PbBr_3 Determined by Single Crystal Neutron Diffractometry

Creators Mashiyama H.

Creators Kawamura Y.

Creators Kasano H.

Creators Asahi T.

Creators Noda Y.

Creators Kimura H.

In order to understand the mechanism of the structural phase transition in CH_3NH_3PbBr_3, neutron diffraction data from the single crystal is analyzed by the least-squares method and the maximum entropy method. The disordered configuration of a methylammonium ion in a cage surrounded by eight PbBr_6 octahedrons is identified unambiguously. With comparing the low-temperature structure, the transition is characterized by the condensation of the rotational motion of the PbBr_6 octahedron around the Pb-Br axis, which accompanies the partial ordering of the methylammonium ion to reduce the site symmetry.

[ISSN]0015-0193

[NCID]AA00644949

info:doi/10.1080/00150190701196435

[isVersionOf] [URI]http://www.tandf.co.uk/journals/titles/00150193.asp