A novel heavy-fermion state in CaCu3Ru4O12
A novel heavy-fermion state in CaCu3Ru4O12
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DOI：
10.1143/jpsj.73.2373
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发表时间：
2004-09-01
影响因子：
1.7
通讯作者：
Ando, Y
中科院分区：
文献类型：
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作者：
Kobayashi, W;Terasaki, I;Ando, Y
我们测量了CaCu_3 Ti_（4-x）Ru_xO_（12）和CaCu_（3-y）Mn_yRu_4 O_（12）的磁化率、比热、电阻率和热电势，发现CaCu_3Ru_4 O_（12）在d电子系统中可以看作是重费米子氧化物。近藤温度接近200 K，磁化率（1.4 × 10（-3）emu/Cu mol）和电子比热系数（28 mJ/（Cu mol K-2））适度增强。低温下电阻率与T-2成正比，满足Kadowaki-Woods关系。重费米子态来自Cu 3d的局域磁矩与Ru 4d的传导电子之间的相互作用。CaCu 3 Ti4-xRuxO 12在x = 1.5 ~ 4之间发生了绝缘体-金属的转变，可以认为是从磁性绝缘体到重费米子金属的转变。
We have measured the susceptibility, specific heat, resistivity, and thermopower of CaCu3Ti4-xRuxO12 and CaCu3-yMnyRu4O12, and have found that CaCu3Ru4O12 can be regarded as a heavy-fermion oxide in d-electron systems. The Kondo temperature is near 200 K, and the susceptibility (1.4 x 10(-3) emu/Cu mol) and the electron specific heat coefficient [28 mJ/(Cu mol K-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 CaCu3Ti4-xRuxO12, which can be regarded as a transition from a magnetic insulator to a heavy-fermion metal.