Structural and Magnetic Properties of Nd₁₈Li₈Co₄₋ₓFeₓO39-y and Nd₁₈Li₈Co₄₋ₓTiₓO39-y
Nd₁₈Li₈Co3FeO39-y, Nd₁₈Li₈CoFe3O39-y and Nd₁₈Li₈Co3TiO39-y have been synthesised and characterised by neutron powder diffraction, magnetometry and Mössbauer spectroscopy. Their cubic structure (Pm3-n, a∼11.9 Å) is based on intersecting <1 1 1> chains comprised of alternating octahedral and trigonal-prismatic coordination sites. These chains lie within hexagonal-prismatic cavities formed by a Nd-O framework. Each compound has an incomplete oxide sublattice (y∼1), with vacancies located around the octahedral sites that lie at the points of chain intersection. These sites are fully occupied by a disordered arrangement of transition-metal cations but only 75% of the remaining octahedral sites are occupied. the trigonal-prismatic sites are fully occupied by lithium except in the case of Nd₁₈Li₈CoFe3O39-y where some iron is present. Antiferromagnetic interactions are present on the Nd sublattice in each composition, but a spin glass forms below 5 K when a high concentration of spins is also present on the octahedral sites.
P. D. Battle et al., "Structural and Magnetic Properties of Nd₁₈Li₈Co₄₋ₓFeₓO39-y and Nd₁₈Li₈Co₄₋ₓTiₓO39-y," Journal of Solid State Chemistry, vol. 184, no. 9, pp. 2580-2587, Elsevier, Sep 2011.
The definitive version is available at http://dx.doi.org/10.1016/j.jssc.2011.07.020
Article - Journal
© 2011 Elsevier, All rights reserved.