Critical properties of the 3D-Heisenberg ferromagnet \chem{CdCr_{2}Se_{4}}

The cubic B20 compound FeGe, which exhibits a near room temperature skyrmion phase, is of great importance not only for fundamental physics such as nonlinear magnetic ordering and solitons but also for future application of skyrmion states in spintronics. In this work, the critical behavior of the cubic FeGe is investigated by means of bulk dc-magnetization. We obtain the critical exponents (β = 0.336 ± 0.004, γ = 1.352 ± 0.003 and β = 5.276 ± 0.001), where the self-consistency and reliability are verified by the Widom scaling law and scaling equations. The magnetic exchange distance is found to decay as r−4.9, which is close to the theoretical prediction of 3D-Heisenberg model (r−5). The critical behavior of FeGe indicates a short-range magnetic interaction. Meanwhile, the critical exponents also imply an anisotropic magnetic coupling in this system.

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“…3 (a–d). All these four constructions exhibit quasi-straight lines in the high field region333435. Apparently, the lines in Fig.…”

Section: Resultsmentioning

confidence: 80%

Critical phenomenon of the near room temperature skyrmion material FeGe

Zhang

Han

Min

et al. 2016

Sci Rep

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“…This is a strong indication that our estimates of error bars are reli- [53] for η and ν and [55] for ω), MC ( [60] for η and ν and [61] for ω), combined MC and High-Temperature analysis from [62], and 6-loop, d = 3 perturbative RG values [2], and −expansion at order 5 [2] and order 6 [48] are also given for comparison. Results for most precise experiments are also included (Isotropic ferromagnets Gd2BrC and Gd2IC from [63] and CdCr2Se4 from [64]). Whenever needed, scaling relations are used in order to express results in terms of η and ν. able.…”

Section: Results For Some Physically Interesting Casesmentioning

confidence: 99%

Precision calculation of critical exponents in the O(N) universality classes with the nonperturbative renormalization group

et al. 2020

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We compute the critical exponents ν, η and ω of O(N ) models for various values of N by implementing the derivative expansion of the nonperturbative renormalization group up to next-to-nextto-leading order [usually denoted O(∂ 4 )]. We analyze the behavior of this approximation scheme at successive orders and observe an apparent convergence with a small parameter -typically between 1/9 and 1/4 -compatible with previous studies in the Ising case. This allows us to give well-grounded error bars. We obtain a determination of critical exponents with a precision which is similar or better than those obtained by most field theoretical techniques. We also reach a better precision than Monte-Carlo simulations in some physically relevant situations. In the O(2) case, where there is a longstanding controversy between Monte-Carlo estimates and experiments for the specific heat exponent α, our results are compatible with those of Monte-Carlo but clearly exclude experimental values. arXiv:2001.07525v1 [cond-mat.stat-mech]

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“…For an ideal model, the modified Arrott plot should display a series of parallel lines in high field region with the same slope, where the slope is defined as S ( T ) = dM 1/ β / d ( H / M ) 1/ γ . The normalized slope ( NS ) is defined as NS = S ( T )/ S ( T C ), which enables us to distinguish the most suitable model by comparing the NS with the ideal value of ‘1’353637. Plots of NS vs. T for the four different models are shown in Fig.…”

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confidence: 99%

Anisotropic magnetic coupling with a two-dimensional characteristic in noncentrosymmetric Cr11Ge19

Han

Zhang

Zhu

et al. 2016

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In this work, we successfully synthesize the single crystal Cr11Ge19. The magnetism of the noncentrosymmetric Cr11Ge19 with itinerant ferromagnetic ground state is thoroughly investigated on the single crystal. Based on the variation measurements including the angular rotation, temperature, and magnetic field dependence of magnetization, we find that this material exhibits strong magnetic anisotropy along the c-axis. To clearly reveal the magnetic interactions, the critical behavior is studied using the modified Arrott plot, the Kouvel-Fisher method, and the critical isotherm technique. Combining these different methods, three main critical exponents (β, γ, and δ) are obtained. The critical exponent β is close to the theoretical prediction of a three-dimensional XY model with spin-dimensionality n = 2, indicating two-dimensional magnetic coupling. Meanwhile, the critical exponent γ suggests that the magnetic interaction is of long-range type with magnetic exchange distance decaying as J(r) ≈ r−4.61. We propose that the ferromagnetic ground state of Cr11Ge19 is formed by the polarized magnetic moments along the c-axis, while the long-range magnetic coupling is established within the ab plane.

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Critical properties of the 3D-Heisenberg ferromagnet \chem{CdCr_{2}Se_{4}}

Cited by 38 publications

References 34 publications

Critical phenomenon of the near room temperature skyrmion material FeGe

Critical phenomenon of the near room temperature skyrmion material FeGe

Precision calculation of critical exponents in the O(N) universality classes with the nonperturbative renormalization group

Anisotropic magnetic coupling with a two-dimensional characteristic in noncentrosymmetric Cr11Ge19

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