Kondo lattice and antiferromagnetic behavior in quaternary CeTAl₄Si₂ (T = Rh, Ir) single crystals

Journal Article · 26 February 2016 · Journal of the Physical Society of Japan

DOI: https://doi.org/10.7566/JPSJ.85.034720 · OSTI ID:1254319

Maurya, Arvind ^[1]; Kulkarni, Ruta ^[1]; Thamizhavel, Arumugam ^[1]; Paudyal, Durga ^[2]; Dhar, Sudesh Kumar ^[1]

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1. Tata Institute of Fundamental Research, Mumbai (India)
2. Ames Lab. and Iowa State Univ., Ames, IA (United States)

Here, we have explored in detail the anisotropic magnetic properties of CeRhAl₄Si₂ and CeIrAl₄Si₂, which undergo two antiferromagnetic transitions, at T_N1 = 12.6 and 15.5 K, followed by a second transition at T_N2 = 9.4 and 13.8 K, respectively, with the [001]-axis as the relatively easy axis of magnetization. The electrical resistivity at ambient and applied pressure provides evidence of Kondo interaction in both compounds, further supported by a reduced value of the entropy associated with the magnetic ordering. The Sommerfeld coefficient γ is inferred to be 195.6 and 49.4 mJ/(mol K²) for CeRhAl₄Si₂ and CeIrAl₄Si₂, respectively, classifying these materials as moderate heavy-fermion compounds. The crystal electric field energy levels are derived from the peak seen in the Schottky heat capacity. Furthermore, we have also performed electronic structure calculations by using the local spin density approximation + U [LSDA+U] approach, which provide physical insights on the observed magnetic behavior of these two compounds.

• Research Organization: Ames Laboratory (AMES), Ames, IA (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC02-07CH11358
• OSTI ID: 1254319
• Report Number(s): IS-J--8966
• Journal Information: Journal of the Physical Society of Japan, Journal Name: Journal of the Physical Society of Japan Journal Issue: 3 Vol. 85; ISSN 0031-9015
• Publisher: Physical Society of JapanCopyright Statement
• Country of Publication: United States
• Language: English