English

Synthesis and physical properties of CeRu$_2$As$_2$ and CeIr$_2$As$_2$

Strongly Correlated Electrons 2019-11-18 v2 Materials Science Superconductivity

Abstract

We studied the physical properties of two Kondo-lattice compounds, CeRu2_2As2_2 and CeIr2_2As2_2, by a combination of electric transport, magnetic and thermodynamic measurements. They are of ThCr2_2Si2_2-type and CaBe2_2Ge2_2-type crystalline structures, respectively. CeRu2_2As2_2 shows localized long-range antiferromagnetic ordering below TNT_N=4.3 K, with a moderate electronic Sommerfeld coefficient γ0\gamma_0=35 mJ/mol\cdotK2^2. A field-induced metamagnetic transition is observed near 2 T below TNT_N. Magnetic susceptibility measurements on aligned CeRu2_2As2_2 powders suggest that it has an easy axis and that the cerium moments align uniaxially along c\mathbf{c} axis. In contrast, CeIr2_2As2_2 is a magnetically nonordered heavy-fermion metal with enhanced γ0\gamma_0>>300 mJ/mol\cdotK2^2. The initial onset Kondo temperatures of the two compounds are respectively 6 K and 30 K. We discuss the role of the crystal structure to the strength of Kondo coupling. This work provides two new dense Kondo-lattice materials for further investigations on electronic correlation, quantum criticality and heavy-electron effects.

Keywords

Cite

@article{arxiv.1909.04447,
  title  = {Synthesis and physical properties of CeRu$_2$As$_2$ and CeIr$_2$As$_2$},
  author = {Kangqiao Cheng and Xiaobo He and Haiyang Yang and Binjie Zhou and Yuke Li and Yongkang Luo},
  journal= {arXiv preprint arXiv:1909.04447},
  year   = {2019}
}

Comments

8 pages, 5+2 figures, 1 table