Structure and properties of La2Mo2O7: A quasi-two-dimensional metallic oxide with strong MoMo bonds
1987; Elsevier BV; Volume: 66; Issue: 1 Linguagem: Inglês
10.1016/0022-4596(87)90228-3
ISSN1095-726X
AutoresAhmad Moini, M. A. Subramanian, Abraham Clearfield, F. J. DiSalvo, W.H. McCarroll,
Tópico(s)Electronic and Structural Properties of Oxides
ResumoSingle crystals of La2Mo2O7, prepared by fused salt electrolysis, were used for structural and electronic characterization. La2Mo2O7 is orthorhombic with a = 6.034Å, b = 12.236 Å, and c = 3.888 Å. The dominant feature of the structure, which was refined in space group Pnnm, is Mo2O10 units formed by edge-sharing MoO6 octahedra which contain MoMo distances of only 2.478 Å. These groups then share corners in two dimensions to give rise to MoO layers which are held together by the lanthanum ions. The relationship of the La2Mo2O7 structure to those of other reduced oxides is discussed. La2Mo2O7 is a metallic conductor down to 125 K where a phase transition takes place. A similar transition is seen in the magnetic susceptibility. The anomalous electric and magnetic behavior of this compound may be associated with a charge density wave instability of the type often found in quasi-two-dimensional materials.
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