Ueland, B. G.; Kreyssig, A.; Mun, E. D.; Lynn, J. W.; Harriger, L. W.; Pratt, D. K.; Prokes, K.; Huesges, Z.; Toft-Petersen, R.; Sauerbrei, S.; Saunders, S. M.; Furukawa, Y.; Bud'ko, S. L.; McQueeney, R. J.; Canfield, P. C.; Goldman, A., I: Magnetic-field effects on the fragile antiferromagnetism in YbBiPt. Physical Review B 99 (2019), p. 184431/1-12
10.1103/PhysRevB.99.184431

Abstract:
We present neutron-diffraction data for the cubic-heavy-fermion YbBiPt that show broad magnetic diffraction peaks due to the fragile short-range antiferromagnetic (AFM) order persist under an applied magnetic-field H. Our results for H ⊥ [¯1 1 0] and a temperature of T = 0.14(1)K show that the (1/2, 1/2, 3/2) magnetic diffraction peak can be described by the same two-peak line shape found for μ0H = 0 T below the Néel temperature of TN = 0.4K. Both components of the peak exist for μ0H < 1.4 T, which is well past the AFM phase boundary determined from our new resistivity data. Using neutron-diffraction data taken at T = 0.13(2)K for H || [0 0 1] or [1 1 0], we show that domains of short-range AFM order change size throughout the previously determined AFM and non-Fermi liquid regions of the phase diagram, and that the appearance of a magnetic diffraction peak at (1/2, 1/2, 1/2) at μ0H ≈ 0.4 T signals canting of the ordered magnetic moment away from [1 1 1]. The continued broadness of the magnetic diffraction peaks under a magnetic field and their persistence across the AFM phase boundary established by detailed transport and thermodynamic experiments present an interesting quandary concerning the nature of YbBiPt’s electronic ground state.