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

• Published in: arXiv.org
• Main Authors: Ueland, B G, Saunders, S M, Bud'ko, S L, Schmiedeshoff, G M, Canfield, P C, Kreyssig, A, Goldman, A I
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 05.11.2015
• Subjects: Ambient temperature; Antiferromagnetism; Crystal structure; Crystallinity; Crystallography; Cubic lattice; Diffraction; Diffraction patterns; Dilatometry; Electric fields; Fermions; High resolution; Kondo temperature; Phase transitions; Physics - Strongly Correlated Electrons; Symmetry; Thermal expansion; X-ray diffraction
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1511.01822

YbBiPt is a heavy-fermion compound possessing significant short-range antiferromagnetic correlations below a temperature of \(T^{\textrm{*}}=0.7\) K, fragile antiferromagnetic order below \(T_{\rm{N}}=0.4\) K, a Kondo temperature of \(T_{\textrm{K}} \approx1\) K, and crystalline-electric-field splitting on the order of \(E/k_{\textrm{B}}=1\,\textrm{-}\,10\) K. 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 \(\approx6\,\textrm{-}\,10\times10^{-5}\) \AA, 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 \(\approx18\) 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 Yb\(^{3+}\) residing on a site with either cubic or less than cubic point symmetry.