Magnetic order in TbCo2Zn20 and TbFe2Zn20

TitleMagnetic order in TbCo2Zn20 and TbFe2Zn20
Publication TypeJournal Article
Year of Publication2010
AuthorsTian W, Christianson AD, Zarestky JL, Jia S, Bud'ko SL, Canfield PC, Piccoli PMB, Schultz AJ
Journal TitlePhysical Review B
Date Published04/01
ISBN Number1098-0121
Accession NumberISI:000277210200073
Keywordscecr2al20, co, RH, ru

We report neutron diffraction studies of TbCo2Zn20 and TbFe2Zn20, two isostructural compounds which exhibit dramatically different magnetic behavior. In the case of TbCo2Zn20, magnetic Bragg peaks corresponding to antiferromagnetic order are observed below T-N approximate to 2.5 K with a propagation vector of (0.5 0.5 0.5). On the other hand, TbFe2Zn20 undergoes a ferromagnetic transition at temperatures as high as 66 K which shows a high sensitivity to sample-to-sample variations. Two samples of TbFe2Zn20 with the same nominal compositions but with substantially different magnetic ordering temperatures (T-c approximate to 51 and 66 K) were measured by single-crystal neutron diffraction. Structural refinements of the neutron diffraction data find no direct signature of atomic site disorder between the two TbFe2Zn20 samples except for subtle differences in the anisotropic thermal parameters. The differences in the anisotropic thermal parameters between the two samples are likely due to very small amounts of disorder. This provides further evidence for the extreme sensitivity of the magnetic properties of TbFe2Zn20 to small sample variations, even small amounts of disorder.

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