title: Coupled commensurate cation and charge modulation in the tunneled structure, Na(0.40(2))MnO(2).
abstract: Na(0.40(2))MnO(2) belongs to a family of mixed Mn(3+) and Mn(4+) porous oxides that contains both octahedral and square pyramidal Mn-O units. Neutron and synchrotron radiation studies identify the presence of both sodium ordering (T(Na) ≈ 310 K) and Mn charge and orbital ordering. Below T(Na), the centrosymmetric Pbam structure adopts an (ab 4c) supercell of Pnnm symmetry that accommodates a coupled commensurate modulation down the c-axis channels of both Na position and occupancy with Mn valence.
authors.affiliation: NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States.
authors.forename: Izabela
authors.initials: I
authors.lastname: Kruk
authors.forename: Pawel
authors.initials: P
authors.lastname: Zajdel
authors.forename: Wouter
authors.initials: W
authors.lastname: van Beek
authors.forename: Ioanna
authors.initials: I
authors.lastname: Bakaimi
authors.forename: Alexandros
authors.initials: A
authors.lastname: Lappas
authors.forename: Chris
authors.initials: C
authors.lastname: Stock
authors.forename: Mark A
authors.initials: MA
authors.lastname: Green