Magnetic Structure of the Oxygen-Deficient Perovskite YBaCuFeO5+δ

Alvaro W. Mombru, Christos Christides, Alexandros Lappas, Kosmas Prassides, M. Pissas, C. Mitros, D. Niarchos

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34 Citations (Scopus)


The magnetic and crystal structures of the oxygen-deficient layered perovskite YBaCuFeO5+δ have been determined with powder neutron diffraction methods. It crystallizes in the noncentrosymmetric tetragonal space group P4mm with a = 3.8707(2) Å and c = 7.6711(4) Å (at room temperature). Structural motifs of corner-sharing severely elongated CuO5 (Cu-Oeq = 1.936(2) Å, Cu-Oax = 2.35(9) Å) and slightly squashed FeO5 (Fe-Oeq = 2.03(3) Å, Fe-Oax = 1.82(9) Å) square pyramids result in a novel lamellar structure with ordered oxygen defects. Local magnetic moments directed perpendicular to the unique axis (μ perpendicular to c, μ = 2.51 (15) μB at room temperature) appear at the Fe3+ sites at 442.4(5) K. The magnetic unit cell results by doubling the chemical one along all three crystallographic directions (magnetic propagation vector, k = (1/2,1/2,1/2))- Despite the long separation between successive FeO2 layers (~7.7 Å), the magnetic behavior can be successfully described by a three-dimensional Heisenberg spin Hamiltonian with a critical exponent β = 0.366(8). No evidence of ordering of the Cu sublattice is found on cooling to room temperature.

Original languageEnglish
Pages (from-to)1255-1258
Number of pages4
JournalInorganic chemistry
Issue number7
Publication statusPublished - 1994 Mar 1
Externally publishedYes

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry


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