High-resolution x-ray diffraction study of the heavy-fermion compound YbBiPt

Journal Article · 29 November 2015 · Physical Review. B, Condensed Matter and Materials Physics

DOI: https://doi.org/10.1103/PhysRevB.92.184111 · OSTI ID:1235586

Ueland, B. G. ^[1]; Saunders, S. M. ^[1]; Bud'ko, S. L. ^[1]; Schmiedeshoff, G. M. ^[2]; Canfield, P. C. ^[1]; Kreyssig, A. ^[1]; Goldman, A. I. ^[1]

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1. Ames Lab., Ames, IA (United States); Iowa State Univ., Ames, IA (United States)
2. Occidental College, Los Angeles, CA (United States)

In this study, YbBiPt is a heavy-fermion compound possessing significant short-range antiferromagnetic correlations below a temperature of T*=0.7K, fragile antiferromagnetic order below T_N = 0.4K, a Kondo temperature of T_K ≈ 1K, and crystalline-electric-field splitting on the order of E/k_B = 1 – 10K. Whereas the compound has a face-centered-cubic lattice at ambient temperature, certain experimental data, particularly those from studies aimed at determining its crystalline-electric-field scheme, suggest that the lattice distorts at lower temperature. Here, we present results from high-resolution, high-energy x-ray diffraction experiments which show that, within our experimental resolution of ≈ 6 – 10 × 10^–5 Å, no structural phase transition occurs between T = 1.5 and 50 K. In combination with results from dilatometry measurements, we further show that the compound's thermal expansion has a minimum at ≈ 18 K and a region of negative thermal expansion for 9 ≲ T ≲ 18 K. Despite diffraction patterns taken at 1.6 K which indicate that the lattice is face-centered cubic and that the Yb resides on a crystallographic site with cubic point symmetry, we demonstrate that the linear thermal expansion may be modeled using crystalline-electric-field level schemes appropriate for Yb³⁺ residing on a site with either cubic or less than cubic point symmetry.

• Research Organization: Ames Laboratory (AMES), Ames, IA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• Grant/Contract Number: AC02-06CH11357; AC02-07CH11358
• OSTI ID: 1235586
• Report Number(s): IS-J-8891
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Journal Name: Physical Review. B, Condensed Matter and Materials Physics Journal Issue: 18 Vol. 92; ISSN 1098-0121; ISSN PRBMDO
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English