High temperature ferromagnetism in GdFe2Zn20: large, local moments embedded in the nearly ferromagnetic Fermi liquid compound YFe2Zn20

S. Jia; S. L. Bud'ko; G. D. Samolyuk; P. C. Canfield

paper

High temperature ferromagnetism in GdFe2Zn20: large, local moments embedded in the nearly ferromagnetic Fermi liquid compound YFe2Zn20

arXiv:cond-mat/0606615

Abstract

The RFe $_{2}$ Zn $_{20}$ series manifests strongly correlated electron behavior for the non-magnetic R = Y member and remarkably high temperature, ferromagnetic ordering ( $T_{C}$ = 86 K) for the local moment bearing R = Gd member (a compound that is less than 5% atomic Gd). In contrast, the isostructural RCo $_{2}$ Zn $_{20}$ series manifests a more typical ordering temperature ( $T_{N}$ = 5.7 K for GdCo $_{2}$ Zn $_{20}$ ) and YCo $_{2}$ Zn $_{20}$ does not show signs of correlated electron behavior. Studies of R(Fe $_{x}$ Co $_{1 - x}$ ) $_{2}$ Zn $_{20}$ (R = Gd, Y), combined with bandstructure calculations for the end members, reveal that YFe $_{2}$ Zn $_{20}$ is a nearly ferromagnetic Fermi liquid and that the remarkably high $T_{C}$ associated with GdFe $_{2}$ Zn $_{20}$ is the result of submerging a large local moment into such a highly polarizable matrix. These results indicate that the RFe $_{2}$ Zn $_{20}$ series, and more broadly the RT $_{2}$ Zn $_{20}$ (T = Fe, Co, Ni, Mn, Ru, Rh, Os, Ir, Pt) isostructural family of compounds, offer an exceptionally promising phase space for the study of the interaction between local moment and correlated electron effects near the dilute R limit.