Magnetic properties and critical behaviors of the nodal-line semimetal candidate ErIn3

The AuCu3-type intermetallic compoundsReIn3(Re= a rare earth ion) with type-IV magnetic space groups are predicted to show topologically nontrivial electronic states. Here, we grow ErIn3single crystals, and study their magnetic properties and critical behaviors by means of the magnetic susceptibility, and magnetization isotherm measurements. Combining a detailed analysis of the magnetic susceptibility and isothermal magnetization, we find that this compound harbors a complicated magnetic phase diagram, and its magnetic moment arrangement appears not to simply follow the fashion as observed in the isostructural counterpart GdIn3(it adopts a conventional type-Cmagnetic structure that belongs to type-IV magnetic space groups). A careful study of the magnetic properties around the antiferromagnetic (AFM)-paramagnetic transition yields the critical exponentsβ= 0.309 (0.297),γ= 1.117 (1.038), andδ= 4.617 (4.454), indicating that the tricritical mean field model or the three-dimensional Ising model works for ErIn3's magnetic behaviors and the presence of a long-range AFM interaction therein. Besides, the exchange interaction distanceJ(r) ∼r-4.665as well confirms a long-range magnetic coupling in ErIn3. Our results offer the clues that the magnetic structure varies from one member ofReIn3family to another, and to confirm their electronic features in the AFM phases further experimental and theoretical studies are still desired.

Large magnetic entropy change and prediction of magnetoresistance using a magnetic field in La0.5Sm0.1Sr0.4Mn0.975In0.025O3

A detailed study of the structural, magnetic, magnetocaloric and electrical effect properties in polycrystalline manganite La_0.5Sm_0.1Sr_0.4Mn_0.975In_0.025O₃ is presented. The X-ray diffraction pattern is consistent with a rhombohedral structure with R3̄c space group. Experimental results revealed that our compound prepared via a sol-gel method exhibits a continuous (second-order) ferromagnetic (FM) to paramagnetic (PM) phase transition around the Curie temperature (T _C = 300 K). In addition, the magnetic entropy change was found to reach 5.25 J kg^-1 K^-1 under an applied magnetic field of 5 T, corresponding to a relative cooling power (RCP) of 236 J kg^-1. We have fitted the experimental data of resistivity using a typical numerical method (Gauss function). The simulation values such as maximum resistivity (ρ _max) and metal-semiconductor transition temperature (T _M-Sc), calculated from this function, showed a perfect agreement with the experimental data. The shifts of these parameters as a function of magnetic field for our sample have been interpreted. The obtained values of β and γ, determined by analyzing the Arrott plots, are found to be T _C = 298.66 ± 0.64 K, β = 0.325 ± 0.001 and γ = 1.25 ± 0.01. The critical isotherm M (T _C, μ ₀ H) gives δ = 4.81 ± 0.01. These critical exponent values are found to be consistent and comparable to those predicted by the three-dimensional Ising model with short-range interaction. Thus, the Widom scaling law is fulfilled.

Critical phenomena and estimation of the spontaneous magnetization from a mean field analysis of the magnetic entropy change in La0.7Ca0.1Pb0.2Mn0.95Al0.025Sn0.025O3

In the present work, we have studied the universal critical behavior in the perovskite-manganite compound La_0.7Ca_0.1Pb_0.2Mn_0.95Al_0.025Sn_0.025O₃. Experimental results revealed that all samples exhibit a second-order magnetic phase transition. To study the critical behavior of the paramagnetic–ferromagnetic transition, various techniques such as modified Arrott plots, the Kouvel–Fisher method and critical isotherm analysis were used to determine the values of the Curie temperature T_C, as well as the critical exponents β (corresponding to the spontaneous magnetization), γ (corresponding to the initial susceptibility) and δ (corresponding to the critical magnetization isotherm). The critical exponent values for our sample are consistent with the prediction of the mean field model (β = 0.46, γ = 1.0, and δ = 2.94 at an average T_C = 302.12 K), indicating that the magnetic interactions are long-range. The reliability of the critical exponent values was confirmed by the Widom scaling relation (WSR) and the universal scaling hypothesis. Moreover, to estimate the spontaneous magnetization of La_0.7Ca_0.1Pb_0.2Mn_0.95Al_0.025Sn_0.025O₃ perovskite, we used the magnetic entropy change (ΔS_M), obtained from isothermal magnetization. The results obtained through this approach are compared to those obtained from classical analysis using Arrott curves. An excellent agreement is found between this approach and the one obtained from the extrapolation of the Arrott curves.

In the present work, we have studied the universal critical behavior in the perovskite-manganite compound La_0.7Ca_0.1Pb_0.2Mn_0.95Al_0.025Sn_0.025O₃.