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Mass-Enhanced Fermi Liquid Ground State in Na$_{1.5}$Co$_2$O$_4$

K. Miyoshi·E. Morikuni·K. Fujiwara·J. Takeuchi·T. Hamasaki
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Abstract

Magnetic, transport, and specific heat measurements have been performed on layered metallic oxide Na$_{1.5}$Co$_2$O$_4$ as a function of temperature $T$. Below a characteristic temperature $T^*$=30$-$40 K, electrical resistivity shows a metallic conductivity with a $T^2$ behavior and magnetic susceptibility deviates from the Curie-Weiss behavior showing a broad peak at $\sim$14 K. The electronic specific heat coefficient $γ$ is $\sim$60 mJ/molK$^2$ at 2 K. No evidence for magnetic ordering is found. These behaviors suggest the formation of mass-enhanced Fermi liquid ground state analogous to that in $d$-electron heavy fermion compound LiV$_2$O$_4$.

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K. Miyoshi, E. Morikuni, K. Fujiwara, J. Takeuchi, T. Hamasaki. 2004-03-01. Mass-Enhanced Fermi Liquid Ground State in Na$_{1.5}$Co$_2$O$_4$. https://doi.org/10.1103/physrevb.69.132412

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