title: Pressure-induced transformation of 6H hexagonal to 3C Perovskite structure in PbMnO3.
abstract: A tetragonal perovskite PbMnO(3) was obtained by treating the 6H hexagonal perovskite phase at 15 GPa and 1273 K. Structural analysis using synchrotron X-ray diffraction suggested that PbMnO(3) crystallizes in the centrosymmetric space group P4/mmm, unlike PbTiO(3) and PbVO(3) which have a polar structure in space group P4mm. Iodometric titration revealed the presence of the oxygen deficiency of x = 0.06 for PbMnO(3-x). The hexagonal 6H and the 3C perovskite phases exhibited antiferromagnetic ordering at 155 and 20 K, respectively.
authors.affiliation: Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan. oka@msk.kuicr.kyoto-u.ac.jp
authors.forename: Kengo
authors.initials: K
authors.lastname: Oka
authors.forename: Masaki
authors.initials: M
authors.lastname: Azuma
authors.forename: Shigeto
authors.initials: S
authors.lastname: Hirai
authors.forename: Alexei A
authors.initials: AA
authors.lastname: Belik
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kojitani
authors.forename: Masaki
authors.initials: M
authors.lastname: Akaogi
authors.forename: Mikio
authors.initials: M
authors.lastname: Takano
authors.forename: Yuich
authors.initials: Y
authors.lastname: Shimakawa