x-ray diffraction; magnetic properties; Mossbauer spectroscopy
Abstract :
[en] Nd18Li8Co3FeO39–y, Nd18Li8CoFe3O39–y and Nd18Li8Co3TiO39 39–y have been synthesisd and characterised by neutron powder diffraction, magnetometry and Mossbauer spectroscopy. Their cubic structure (Pm–3n, 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 ion-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.
Disciplines :
Chemistry
Author, co-author :
Battle, Peter; University of Oxford > Inorganic Chemistry
Dutton, Sean E
Grandjean, Fernande ; Université de Liège - ULiège > Département de physique > Département de physique
Long, Gary; Missouri University of Science and Technology > Chemistry
Thammajak, N; Oxford University > Inorganic Chemistry
Wisetsuwannaphum, S
Language :
English
Title :
Structural and magnetic properties of Nd 18Li 8Co 4-xFe xO 39-y and Nd 18Li 8Co 4-xTi xO 39-y
Alternative titles :
[en] Propriétés structurelles et magnétiques de Nd18Li8Co4-xFexO39-y et Nd18Li8Co4-xTixO39-y
Publication date :
2011
Journal title :
Journal of Solid State Chemistry
ISSN :
0022-4596
eISSN :
1095-726X
Publisher :
Academic Press, San Diego, United States - California