Pressure-induced transformation of 6H hexagonal to 3C Perovskite structure in PbMnO3.
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.
Oka
Kengo
K
Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan. oka@msk.kuicr.kyoto-u.ac.jp
Azuma
Masaki
M
Hirai
Shigeto
S
Belik
Alexei A
AA
Kojitani
Hiroshi
H
Akaogi
Masaki
M
Takano
Mikio
M
Shimakawa
Yuich
Y