Introducing a large polar tetragonal distortion into Ba-doped BiFeO3 by low-temperature fluorination.
This article reports on the synthesis and crystallographic and magnetic structure of barium-doped BiFeO3 compounds with approximate composition Bi(1-x)Ba(x)FeO(3-x/2), as well as those of the fluorinated compounds Bi(1-x)Ba(x)FeO(3-x)F(x) (both with x = 0.2, 0.3), prepared by low-temperature fluorination of the oxide precursors using polyvinylidenedifluoride. Whereas the oxide compounds were obtained as cubic (x = 0.2) and slightly tetragonal (x = 0.3, c/a ≈ 1.003) distorted perovskite compounds, a large tetragonal polar distortion was observed for the oxyfluoride compounds (c/a ≈ 1.08 for x = 0.2 and ∼1.05 for x = 0.3), being isostructural to tetragonal PbTiO3. Although described differently in previous reports on Ba-doped BiFeO3, the observed remanent magnetization is found to agree well with the amount of BaFe12O19 only detectable by neutron diffraction and the well-known magnetic properties of BaFe12O19. The oxyfluoride compounds show G-type antiferromagnetic ordering with magnetic moments lying in the a/b plane.
Joint Research Laboratory Nanomaterials and ‡Institute of Materials Science, Technische Universität Darmstadt , Jovanka-Bontschits-Straße 2, 64287 Darmstadt, Germany.
Oliver
O
Clemens
Robert
R
Kruk
Eric A
EA
Patterson
Christoph
C
Loho
Christian
C
Reitz
Adrian J
AJ
Wright
Kevin S
KS
Knight
Horst
H
Hahn
Peter R
PR
Slater
D001464:Barium / Q000737:chemistry*; D001729:Bismuth / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D054879:Halogenation; D060328:Magnetic Phenomena; D015394:Molecular Structure; D013696:Temperature
D005290:Ferric Compounds; D001464:Barium; D001729:Bismuth