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arXiv · 0708.1291

Unusual heavy-mass nearly ferromagnetic state with a surprisingly large Wilson ratio in the double layered ruthenates (Sr$_{1-x}$Ca$_{x}$)$_{3}$Ru$_{2}$O$_{7}$

Zhe Qu·Leonard Spinu·Huiqiu Yuan·Vladimir Dobrosavljevic·Wei Bao·Jeffrey W. Lynn·M. Nicklas·Jin Peng·Tijiang Liu·David Fobes·Etienne Flesch·Z. Q. Mao
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Abstract

We report an unusual nearly ferromagnetic, heavy-mass state with a surprisingly large Wilson ratio $R_{\textrm{w}}$ (e.g., $R_{\textrm{w}}\sim$ 700 for $x =$ 0.2) in double layered ruthenates (Sr$_{1-x}$Ca$_{x}$)$_{3}$Ru$_{2}$O$_{7}$ with 0.08 $< x <$ 0.4. This state does not evolve into a long-range ferromagnetically ordered state despite considerably strong ferromagnetic correlations, but freezes into a cluster-spin-glass at low temperatures. In addition, evidence of non-Fermi liquid behavior is observed as the spin freezing temperature of the cluster-spin-glass approaches zero near $x \approx$ 0.1. We discuss the origin of this unique magnetic state from the Fermi surface information probed by Hall effect measurements.

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Zhe Qu, Leonard Spinu, Huiqiu Yuan, Vladimir Dobrosavljevic, Wei Bao, Jeffrey W. Lynn, M. Nicklas, Jin Peng, Tijiang Liu, David Fobes, Etienne Flesch, Z. Q. Mao. 2008-10-27. Unusual heavy-mass nearly ferromagnetic state with a surprisingly large Wilson ratio in the double layered ruthenates (Sr$_{1-x}$Ca$_{x}$)$_{3}$Ru$_{2}$O$_{7}$. https://doi.org/10.1103/physrevb.78.180407

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