Quasi-One-Dimensional Spin Dynamics in $d$-Electron Heavy-Fermion Metal Y${}_{1-x}$Sc${}_x$Mn${}_2$

Abstract

Slow spin fluctuations ($\hat{I}½<10^{12}$ s${}^{-}1$) observed by the muon spin relaxation technique in Y${}_{1-x}$Sc${}_x$Mn${}_2$ exhibits a power law dependence on temperature ($\hat{I}½\propto T^{\hat{I}}\pm$), where the power converges asymptotically to unity ($\hat{I}\pm \to 1$) as the system moves away from spin-glass instability with increasing Sc content $x$. This linear $T$ dependence, which is common to that observed in LiV${}_2$O${}_4$, is in line with the prediction of the "intersecting Hubbard chains" model for a metallic pyrochlore lattice, suggesting that the geometrical constraints to t2g bands specific to the pyrochlore structure serve as a basis of the $d$-electron heavy-fermion state.

5 pages, 4 figures, to appear in J. Phys. Soc. Jpn