English

Heavy fermion behavior in the quasi-one-dimensional Kondo lattice CeCo2Ga8

Strongly Correlated Electrons 2017-07-05 v3 Materials Science

Abstract

Dimensionality plays an essential role in determining the anomalous non-Fermi liquid properties in heavy fermion systems. So far most heavy fermion compounds are quasi-two-dimensional or three-dimensional. Here we report the synthesis and systematic investigations of the single crystals of the quasi-one-dimensional Kondo lattice CeCo2_2Ga8_8. Resistivity measurements at ambient pressure reveal the onset of coherence at T20T^*\approx 20\,K and non-Fermi liquid behavior with linear temperature dependence over a decade in temperature from 2 K to 0.1 K. The specific heat increases logarithmically with lowering temperature between 10 K and 2 K and reaches 800 mJ/mol K2^2 at 1 K, suggesting that CeCo2_2Ga8_8 is a heavy fermion compound in the close vicinity of a quantum critical point. Resistivity measurements under pressure further confirm the non-Fermi liquid behavior in a large temperature-pressure range. The magnetic susceptibility is found to follow the typical behavior for a one-dimensional (1D) spin chain from 300 K down to TT^*, and first-principles calculations predict flat Fermi surfaces for the itinerant ff-electron bands. These suggest that CeCo2_2Ga8_8 is a rare example of the quasi-1D Kondo lattice, but its non-Fermi liquid behaviors resemble those of the quasi-two-dimensional YbRh2_2Si2_2 family. The study of the quasi-one-dimensional CeCo2_2Ga8_8 family may therefore help us to understand the role of dimensionality on heavy fermion physics and quantum criticality.

Keywords

Cite

@article{arxiv.1608.07013,
  title  = {Heavy fermion behavior in the quasi-one-dimensional Kondo lattice CeCo2Ga8},
  author = {Le Wang and Zhaoming Fu and Jianping Sun and Min Liu and Wei Yi and Changjiang Yi and Yongkang Luo and Yaomin Dai and Guangtong Liu and Yoshitaka Matsushita and Kazunari Yamaura and Li Lu and Jin-Guang Cheng and Yi-feng Yang and Youguo Shi and Jianlin Luo},
  journal= {arXiv preprint arXiv:1608.07013},
  year   = {2017}
}

Comments

11 pages, 7 figures, 2 tables