A novel heavy-fermion state in CaCu_3Ru_4O12

Abstract

We have measured susceptibility, specific heat, resistivity, and thermopower of CaCu${}_3$Ti${}_{4-x}$Ru${}_x$O${}_{12}$ and CaCu${}_{3-y}$Mn${}_y$Ru${}_4$O${}_{12}$, and have found that CaCu${}_3$Ru${}_4$O${}_{12}$ can be regarded as a heavy-fermion oxide in d-electron systems. The Kondo temperature is near 200 K, and the susceptibility (1.4$\times 10^{-3}$ emu/Cu mol) and the electron specific heat coefficient (28 mJ/Cu molK${}^2$) are moderately enhanced. The resistivity is proportional to $T^2$ at low temperatures, and satisfies the Kadowaki-Woods relation. The heavy-fermion state comes from the interaction between the localized moment of Cu 3d and the conduction electron of Ru 4d. An insulator-metal transition occurs between $x=1.5$ and 4 in CaCu${}_3$Ti${}_{4-x}$Ru${}_x$O${}_{12}$, which can be regarded as a transition from magnetic insulator to heavy-fermion metal.

4 pages, 5 figures, submitted to J. Phys. Soc. Jpn

References in corpus (3)

• A first-principles study of the structure and lattice dielectric response of CaCu{3}Ti{4}O{12}
• Antiferromagnetism in CaCu${}_3$Ti${}_4$O${}_{12}$ studied by magnetic Raman spectroscopy
• Universal charge transport of the Mn oxides in the high temperature limit

Cited by in corpus (17)

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• CaCu${}_3$Ru${}_4$O${}_{12}$: a high Kondo-temperature transition metal oxide
• Observation of flat bands due to band hybridization in 3d-electron heavy-fermion compound CaCu3Ru4O12
• Strong Correlation Effects of A-site Ordered Perovskite CaCu3Ti4O12 revealed by Angle-Resolved Photoemission Spectroscopy
• Unraveling the origin of Kondo-like behavior in the 3$d$-electron heavy-fermion compound YFe${}_2$Ge${}_2$
• Evidence for a Ru${}^{4+}$ Kondo Lattice in LaCu${}_3$Ru${}_4$O${}_{12}$
• High-field magnetization and magnetoresistance of the $A$-site ordered perovskite oxide CaCu${}_3$Ti${}_{4-x}$Ru${}_x$O${}_{12}$~($0\le x\le 4$)
• An emerging global picture of heavy fermion physics
• Kondo-like behavior in a mixed valent oxypnictide $\mathrm{L}{\mathrm{a}}_3\mathrm{C}{\mathrm{u}}_4{\mathrm{P}}_4{\mathrm{O}}_2$
• Symmetry-enforced heavy-fermion physics in the quadruple-perovskite CaCu3Ir4O12
• Magnon Damping as a Probe of Kondo Coupling in Magnetically Ordered Systems
• Mass enhancement and metal-nonmetal transition driven by d-f hybridization in perovskites La1-xPrxCuO3
• Variation of strong correlation effects in A-site ordered perovskites CaCu3Ti4-xRuxO12: Photoemission and inverse photoemission studies