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Exotic Heavy-Fermion State in Filled Skutterudite SmOs4Sb12

Shotaro Sanada·Yuji Aoki·Hidekazu Aoki·Akihisa Tsuchiya·Daisuke Kikuchi·Hitoshi Sugawara·Hideyuki Sato
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Abstract

Specific heat and transport measurements have revealed an unconventional heavy-fermion (HF) state in SmOs4Sb12 single crystals. The electronic specific-heat coefficient (gamma=0.82 J/K^2mol) and the coefficient (A) of the quadratic temperature dependence of electrical resistivity are largely enhanced, although the ratio A/gamma^2 is reduced from the Kadowaki-Woods ratio of HF materials. Both gamma and A do not show any significant decrease in applied field in contrast with Ce-based HF compounds, suggesting an unconventional origin of the heavy quasiparticles. A weak ferromagnetic ordering sets in below about 3 K, probably originating in the itinerant quasiparticles.

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Shotaro Sanada, Yuji Aoki, Hidekazu Aoki, Akihisa Tsuchiya, Daisuke Kikuchi, Hitoshi Sugawara, Hideyuki Sato. 2004-12-13. Exotic Heavy-Fermion State in Filled Skutterudite SmOs4Sb12. https://doi.org/10.1143/jpsj.74.246

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