arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0811.4344cond-mat.str-el
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有序钙钛矿ACu3Ru4O12(A = Na,Ca,La)的重质量行为

Heavy-Mass Behavior of Ordered Perovskites ACu3Ru4O12 (A = Na, Ca, La)

Soutarou Tanaka, Nobuhiro Shimazui, Hiroshi Takatsu, Shingo Yonezawa, Yoshiteru Maeno

摘要:

我们合成了ACu_3Ru_4O_(12)(A = Na,Na_(0.5)Ca_(0.5)La_(0.5),Ca),并测量了它们的直流磁化率、交流磁化率、比热和电阻率,以研究异价取代的影响。仅在CaCu 3Ru 4 O 12中观察到200 K附近的DC磁化强度的宽峰,这表明由于局域化的Cu 2+离子引起的近藤效应。然而,电子比热系数表现出大的值不仅为CaCu 3Ru 4 O 12,但也为所有其他样品。此外,我们的样品的Wilson比和Kadowaki-Woods比都与其他重费米子化合物的值相似。这些结果质疑近藤效应作为质量增强的主要来源,而是表明巡游Ru电子之间的相关性的重要性。

英文摘要:

We synthesized ACu3Ru4O12 (A = Na, Na0.5Ca0.5, Ca, Ca0.5La0.5, La) and measured their DC magnetization, AC susceptibility, specific heat, and resistivity, in order to investigate the effects of the hetero-valent substitution. A broad peak in the DC magnetization around 200 K was observed only in CaCu3Ru4O12, suggesting the Kondo effect due to localized Cu2+ ions. However, the electronic specific heat coefficients exhibit large values not only for CaCu3Ru4O12 but also for all the other samples. Moreover, the Wilson ratio and the Kadowaki-Woods ratio of our samples are all similar to the values of other heavy-fermion compounds. These results question the Kondo effect as the dominant origin of the mass enhancement, and rather indicate the importance of correlations among itinerant Ru electrons.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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