Abstract
The compound CuFe 2(P 2O 7) 2 crystallises in the monoclinic system with space group P2 1/ n. The crystal structure is characterised by the presence of centrosymmetric FeCuFe trimers with intra-trimer superexchange interactions. The magnetic interactions between trimers occur through super-superexchange paths consisting of PO 4 groups connecting the trimers formed by FeO 6 octahedra and square planar CuO 4 groups. Susceptibility measurements indicate an antiferromagnetic behaviour at low temperature. Neutron powder diffraction confirms this and the determined Néel temperature is T N=15.5(5) K. The propagation vector of the magnetic structure is k =(1/2,0,1/2) , the ions inside a trimer are coupled ferromagnetically and the magnetic moments are all oriented along the b axis. The value of the staggered moments at 1.5 K are 0.83(6) and 4.88(4) μ B for Cu 2+ and Fe 3+ ions, respectively. The conditions to be satisfied by the exchange interactions in order to get the observed magnetic structure as the stable ground state are discussed.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call