2024/09/06 by A. N. Azarevich, Azarevich, A. N., О.Н. Хрыкина +29 · 1 citation
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Iron-based superconductors research #Magnetic Properties of Alloys #Rare-earth and actinide compounds #Strongly Correlated Electrons (cond-mat.str-el)
paper · pdf · doi:10.48550/arxiv.2409.04139
openalex publication_date 2024/09/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The presented studies of resistivity (R), thermal conductivity (k) and specific heat (C) at low temperature 1.8-7 K in magnetic field up to 90 kOe made it possible to detect for the first time the exponential field dependences R(H), 1/k(H), C(H) ∼ exp(-μ\rm effH/kBT) of the charge transport and thermal characteristics in the so-called antiferroquadrupole (AFQ) phase of the archetypal heavy-fermion CeB6 hexaboride. From magnetoresistance measurements it is shown that in the AFQ state the effective magnetic moment varies in the range μ\rm eff(T) = 1.4-1.9μB, and its value is very close to μ\rm eff(τ)(T) = 2μB, derived from the field dependence of the relaxation time |tau(H) observed in the heat capacity and thermal conductivity experiments. The phenomenological model proposed here allowed us to attribute the magnetic moments to spin droplets (ferrons), that appear in the bulk AFQ phase of CeB6 crystals. The relevant electron phase separation at the nanoscale, manifested by dynamic charge stripes, that leads to the formation of ferrons, was revealed from the analysis of low-temperature X-ray diffraction experiments using the maximum entropy method. We argue that the Jahn-Teller collective mode of B6 clusters is responsible for the charge stripe formation, which subsequently induces transverse quasi-local vibrations of Ce ions in the form of pairs and triples. These lead to 4f-5d spin fluctuations providing spin-polarons (ferrons) in the CeB6 matrix.