A new cobaltite with a tubular structure: Bi{sub 3.7}Sr{sub 11.4}Co{sub 8}O{sub 28{minus}{delta}}, the n = 2 member of the series [Bi{sub 2}Sr{sub 2}CoO{sub 6}]{sub n}[Sr{sub 8}Co{sub 6}O{sub 16{minus}{delta}}]
- CNRS UMR, Caen (France). Lab. CRISMAT
A cobaltite, Bi{sub 3.7}Sr{sub 11.4}Co{sub 8}O{sub 28{minus}{delta}}, with a tubular structure derived from the 2201-type has been synthesized for the first time. This oxide represents, like the homologous manganese phase, the n = 2 member of the large structural [Bi{sub 2}Sr{sub 2}MO{sub 6}]{sub n}[Sr{sub 8}M{sub 6}O{sub 16{+-}{delta}}] family (M = Cu, Co, Mn). Although its structure is similar to the Mn phase, it crystallizes in a different space group, Ammm (or Amm2), with a = 5.5232(2) {angstrom}, b = 23.465(1) {angstrom}, and c = 23.462(1) {angstrom}. The HREM study confirms that the structure consists of the stacking along b (or c) of 2201-type slices with single cobalt-deficient perovskite slices [Sr{sub 8}Co{sub 6}O{sub 6-{delta}}]. But the important difference with the Mn phase concerns the nature of the Co{sub 4} pillars, which are at the intersection of two [Sr{sub 8}Co{sub 6}O{sub 16{minus}{delta}}] slices. They form four corner-sharing CoO{sub 4} tetrahedra instead of MnO{sub 6} octahedra and MnO{sub 5} pyramids. This structural difference means that the Mn and Co phases do not form a complete solid solution. The tubular series Bi{sub 4{minus}y}Sr{sub 12{minus}z}Mn{sub 8{minus}x}Co{sub x}O{sub 28{+-}{delta}} could only be obtained for 0 {le} x {le} 2.5. The magnetic properties of this oxide are very complex and are very sensitive to the oxygen content. In particular, after oxygen pressure annealing, they are characteristic of spin-state transitions with temperature close to 50 and 450 K, similar to those observed in the LaCoO{sub 3} compound.
- OSTI ID:
- 323704
- Journal Information:
- Chemistry of Materials, Journal Name: Chemistry of Materials Journal Issue: 1 Vol. 11; ISSN CMATEX; ISSN 0897-4756
- Country of Publication:
- United States
- Language:
- English
Similar Records
The fourth member of the tubular family [Bi{sub 2}Sr{sub 2}CoO{sub 6}]{sub n}[Sr{sub 8}Co{sub 6}O{sub 16{minus}{delta}}]: Bi{sub 5.8}Sr{sub 15.2}Co{sub 10}O{sub 40{minus}{delta}}
On BSCCO superconductor-related Bi{sub 2}Sr{sub 2}MnO{sub 6+x} and BiPbSr{sub 2}MnO{sub 6}: X-ray absorption spectroscopy and diffraction study
Crystal structure of Bi{sub 6}Sr{sub 8{minus}x}Ca{sub 3+x}O{sub 22} ({minus}0.5 {le} x {le} 1.7): A mixed valence bismuth oxide related to perovskite
Journal Article
·
Tue Nov 30 23:00:00 EST 1999
· Chemistry of Materials
·
OSTI ID:20014835
On BSCCO superconductor-related Bi{sub 2}Sr{sub 2}MnO{sub 6+x} and BiPbSr{sub 2}MnO{sub 6}: X-ray absorption spectroscopy and diffraction study
Journal Article
·
Sat Oct 01 00:00:00 EDT 1994
· Journal of Solid State Chemistry
·
OSTI ID:508698
Crystal structure of Bi{sub 6}Sr{sub 8{minus}x}Ca{sub 3+x}O{sub 22} ({minus}0.5 {le} x {le} 1.7): A mixed valence bismuth oxide related to perovskite
Journal Article
·
Wed Jul 01 00:00:00 EDT 1998
· Chemistry of Materials
·
OSTI ID:638330