Novel universality class for the ferromagnetic transition in the low carrier concentration systems UTeS and USeS exhibiting large negative magnetoresistance
arXiv:1908.07652 · doi:10.1103/PhysRevB.100.064413
Abstract
We report the novel critical behavior of magnetization in low carrier concentration systems UTeS and USeS that exhibit the large negative magnetoresistance around the ferromagnetic transition temperatures T_C ~ 85 and 23 K, respectively. UTeS and USeS crystallize in the same orthorhombic TiNiSi-type crystal structure as those of uranium ferromagnetic superconductors URhGe and UCoGe. We determine the critical exponents, beta for the spontaneous magnetization M_s, gamma for the magnetic susceptibility chi, and delta for the magnetization isotherm at T_C with several methods. The ferromagnetic states in UTeS and USeS have strong uniaxial magnetic anisotropy. However, the critical exponents in the two compounds are different from those in the three-dimensional Ising model with short-range magnetic exchange interactions. Similar sets of the critical exponents have been reported for the uranium ferromagnetic superconductors UGe_2 and URhGe, and uranium intermetallic ferromagnets URhSi, UIr and U(Co_0.98Os_0.02)Al. The universality class of the ferromagnetic transitions in UTeS and USeS may belong to the same one for the uranium compounds. The novel critical phenomenon associated with the ferromagnetic transition is observed not only in the uranium intermetallic ferromagnets with the itinerant 5f electrons but also in the low carrier concentration systems UTeS and USeS with the localized 5f electrons. The large negative magnetoresistance in UTeS and USeS, and the superconductivity in UGe_2 and URhGe share the similarity of their closeness to the ferromagnetism characterized by the novel critical exponents.
8 pages, 6 figures
References in corpus (13)
- Spontaneously polarized half-gapped superconductivity
- Superconductivity on the border of weak itinerant ferromagnetism in UCoGe
- Unconventional Superconductivity
- Extreme magnetic field-boosted superconductivity
- Coexistence of ferromagnetic fluctuations and superconductivity in the actinide superconductor UTe2
- Point Node Gap Structure of Spin-Triplet Superconductor UTe2
- Exponent relations at quantum phase transitions, with applications to metallic quantum ferromagnets
- Itinerant ferromagnetism in actinide 5f electrons system: Phenomenological analysis with spin fluctuation theory
- Unconventional critical scaling of magnetization in uranium ferromagnetic superconductors UGe and URhGe
- Dimensionality driven enhancement of ferromagnetic superconductivity in URhGe
- Novel critical behavior of magnetization in URhSi:Similarities to uranium ferromagnetic superconductors UGe and URhGe
- Superconductivity in the Ferromagnet URhGe under uniaxial pressure
- Crystal structure of the unconventional spin-triplet superconductor UTe2 at low temperature by single crystal neutron diffraction