Stability, oxygen nonstoichiometry, and transformations of the Bi{sub 2}Sr{sub 2}CoO{sub 6+{delta}} ceramic

Journal Article · Sun Feb 15 04:00:00 EST 1998 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1006/jssc.1997.7344· OSTI ID:642191

Zinkevich, M V; Prodan, S A; Zonov, Yu G; Vashook, V V ^[1]

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1. Belarussian Academy of Sciences, Minsk (Belarus). Inst. of General and Inorganic Chemistry

Thermogravimetry at 20--900 C and 10{sup {minus}3}{minus}1 atm of oxygen partial pressure (pO{sub 2}) has been used to establish a region of stability and oxygen nonstoichiometry of the compound Bi{sub 2}Sr{sub 2}CoO{sub 6+{delta}}. This phase was found to be unstable below 850 C at high oxygen partial pressures (air, oxygen), whereas at low oxygen concentrations in the gas phase (pO{sub 2} = 1.5 {times} 10{sup {minus}3}--2 {times} 10{sup {minus}2} atm) it exhibits stability in the entire temperature region under investigation. Within, the region of stability, the oxygen content in Bi{sub 2}Sr{sub 2}CoO{sub 6+{delta}} has been determined under equilibrium conditions as a function of temperature and oxygen partial pressure and the corresponding defect model has been proposed. The annealing of Bi{sub 2}Sr{sub 2}CoO{sub 6+{delta}} outside the region of stability is found to result in the formation of Bi{sub 2}Sr{sub 2}Co{sub 2}O{sub 9} and the binary compounds of the Bi{sub 2}O{sub 3}-SrO system. The kinetics of this transformation has been studied at 700--850 C in a pure oxygen atmosphere and a possible interpretation has been given.

• OSTI ID: 642191
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 1 Vol. 136; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
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CRYSTAL-PHASE TRANSFORMATIONS
EXPERIMENTAL DATA
KINETICS
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STOICHIOMETRY
STRONTIUM OXIDES
TEMPERATURE DEPENDENCE
X-RAY DIFFRACTION