Unconventional critical scaling of magnetization in uranium ferromagnetic superconductors UGe${}_2$ and URhGe

Abstract

We report a dc magnetization study of the critical phenomenon around the ferromagnetic transition temperature T_C in high-quality single crystals of uranium ferromagnetic superconductors UGe2 and URhGe. The critical exponents, beta for the temperature dependence of the magnetization below T_C, gamma for the magnetic susceptibility, and delta for the magnetic isothermal at T_C have been determined with a modified Arrott plot, a Kouvel-Fisher plot, and the scaling analysis. Magnetization in the ferromagnetic state has strong uniaxial magnetic anisotropy in the two compounds. However, the universality class of the critical phenomena do not belong to the three dimensional (3D) Ising system. Although the values of beta in UGe2 and URhGe are close to those in the 3D magnets, the values of gamma are close to unity, that expected from the mean field theory. Similar critical exponents have been reported previously for the 3D Ising ferromagnet UIr where superconductivity appears under high pressure. The critical behavior may be limited to a very narrow Ginzburg critical region of 1 mK because of the strong itinerant character of the 5f electrons in the ferromagnetic superconductor UCoGe where the mean field behavior of the magnetization has been reported. The unconventional critical scaling of magnetization in UGe2, URhGe and UIr cannot be explained via previous approaches to critical phenomena. The ferromagnetic correlation between the 5f electrons differs from that in the 3D Ising system and this difference may be a key point for the understanding of the ferromagnetism where superconductivity emerges.

arXiv comment8 pages, 5 figures

References in corpus (22)

• Superconductivity on the border of weak itinerant ferromagnetism in UCoGe
• Influence of Generic Scale Invariance on Classical and Quantum Phase Transitions
• Quantum Phase Transitions in the Itinerant Ferromagnet ZrZn${}_2$
• Ferromagnetism and Superconductivity in Uranium Compounds
• Tricritical point and wing structure in the itinerant ferromagnet UGe2
• Superconductivity induced by longitudinal ferromagnetic fluctuations in UCoGe
• Magnetically mediated superconductivity: Crossover from cubic to tetragonal lattice
• Microscopic Coexistence of Ferromagnetism and Superconductivity in Single-Crystal UCoGe
• Superconductivity near Itinerant Ferromagnetic Quantum Criticality
• Ferromagnetic Properties of ZrZn${}_2$
• Anisotropic critical magnetic fluctuations in the ferromagnetic superconductor UCoGe
• Electronic Structure of Heavy Fermion Uranium Compounds Studied by Core-Level Photoelectron Spectroscopy
• p-wave superconductivity near a transverse saturation field
• Evidence for weak itinerant long-range magnetic correlations in UGe2
• Dual model for magnetic excitations and superconductivity in UPd2Al3
• Non-Landau damping of magnetic excitations in systems with localized and itinerant electrons
• Pressure Induced Quantum Phase Transitions
• Hyperuniversality of Fully Anisotropic Three-Dimensional Ising Model
• Dilatometry study of the ferromagnetic order in single-crystalline URhGe
• Magnetic relaxation in uranium ferromagnetic superconductors
• Critical Scaling of the Magnetization and Magnetostriction in the Weak Itinerant Ferromagnet UIr
• Phase diagram of UGe2. Whether there are quantum phase transitions ?

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