Ferromagnetic quantum critical point in a Ni<sub>1-x</sub>Rh<sub>x</sub> alloy with x = 0.375

ORAL

Abstract

A chemical substitution-induced ferromagnetic quantum critical point in polycrystalline Ni1−xRhx alloys. Non-Fermi liquid behavior is observed close to the critical concentration xcrit = 0.375, where the Curie temperature vanishes. The electronic specific heat Cel/T, the volume thermal expansion coefficient αV/T, and the Grüneisen ratio Γ ≡ αV/Cel diverge logarithmically upon cooling to absolute zero, providing strong evidence of a ferromagnetic quantum critical point in Ni1−xRhx [1]. We further perform a hyperscaling analysis of the thermodynamic measurements as a function of temperature and magnetic field for Ni1−xRhx with xcrit = 0.375. The obtained critical exponents agree well with the theory proposed by Belitz, Kirkpatrick, and Vojta for a disorder tuned quantum critical point in the preasymptotic region [2].

[1] C.-L. Huang et al., Phys. Rev. Lett. 124, 117203 (2020).

[2] R.-Z. Lin and C.-L. Huang, Phys. Rev. B 105, 024429 (2022).

*This work is supported by the National Science and Technology Council in Taiwan (Grants No. MOST109-2112-M-006-026-MY3 and No. MOST 110-2124-M-006-009) and the Higher Education Sprout Project, Ministry of Education to the Headquarters of University Advancement at NCKU.

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Publication: C.-L. Huang et al., Phys. Rev. Lett. 124, 117203 (2020).
R.-Z. Lin and C.-L. Huang, Phys. Rev. B 105, 024429 (2022).

Presenters

  • Chien-Lung Huang

    • Department of Physics, National Cheng Kung University

Authors

  • Chien-Lung Huang

    • Department of Physics, National Cheng Kung University

  • Rong-Zhu Lin

    • Department of Physics, National Cheng Kung University