Oxygen vacancy ordering in strontium doped rare earth cobaltate perovskites Ln{sub 1-x}Sr {sub x}CoO{sub 3-{delta}} (Ln = La, Pr and Nd; x > 0.60)

Journal Article · Wed Jun 15 00:00:00 EDT 2005 · Materials Research Bulletin

DOI:https://doi.org/10.1016/j.materresbull.2005.02.020· OSTI ID:20889785

James, M ^[1]; Tedesco, T ^[1]; Cassidy, D J ^[2]; Withers, R L ^[3]

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1. Bragg Institute, Australian Nuclear Science and Technology Organisation, Building 58, ANSTO, PMB 1, Menai NSW 2234 (Australia)
2. Materials and Engineering Sciences, Australian Nuclear Science and Technology Organisation, PMB 1, Menai NSW 2234 (Australia)
3. Research School of Chemistry, Australian National University, Canberra, ACT 0200 (Australia)

A family of Sr-doped perovskite compounds Ln{sub 1-x}Sr {sub x}CoO{sub 3-{delta}} (Ln = La{sup 3+}, Pr{sup 3+} and Nd{sup 3+}; x > 0.60), were prepared by sol-gel chemistry and reaction at 1100 deg. C under 1 atm of oxygen. This structural family has been shown to be present only for rare earth ions larger than Sm{sup 3+} and an upper limit of Sr{sup 2+} solubility in these phases was found to exist between x = 0.90 and 0.95. X-ray diffraction shows oxygen-deficient, simple cubic (Pm-3m) perovskite crystal structures. The combination of electron and powder neutron diffraction reveals that oxygen vacancy ordering occurs, leading to a tetragonal (P4/mmm) superstructure and a doubling of the basic perovskite unit along the crystallographic c-axis. No additional Ln{sup 3+}/Sr{sup 2+} cation ordering was observed.

• OSTI ID: 20889785
• Journal Information: Materials Research Bulletin, Vol. 40, Issue 6; Other Information: DOI: 10.1016/j.materresbull.2005.02.020; PII: S0025-5408(05)00083-8; Copyright (c) 2005 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRYSTALLOGRAPHY
CUBIC LATTICES
DOPED MATERIALS
ELECTRON DIFFRACTION
LANTHANUM IONS
NEODYMIUM IONS
NEUTRON DIFFRACTION
OXIDES
OXYGEN
PEROVSKITE
PRASEODYMIUM IONS
RARE EARTHS
SAMARIUM IONS
SOL-GEL PROCESS
STRONTIUM
STRONTIUM IONS
TETRAGONAL LATTICES
THERMAL GRAVIMETRIC ANALYSIS
VACANCIES
X-RAY DIFFRACTION