Magnetic property of CeFe2-xInx alloys and critical parameters of magnetic phase transition of CeFe1.95In0.05 alloy

Abstract

Magnetic properties of CeFe2-xInx alloys and scaling critical behaviors of CeFe1.95In0.05 alloy are investigated by measuring the magnetic susceptibility and isothermal magneteization. The X-ray diffraction (XRD) patterns show that the solid solubility of the In substituted for the Fe in CeFe2-xInx alloy is limited. Because the intensity diffraction peak of impurity at 2=30.75 and 35.80 in CeFe1.95In0.05 XRD pattern are very low, the effect of impurity on magnetism is not considered in this paper. Magnetic measurements indicate that using 2.5 at.% indium to substitute for Fe in CeFe2 alloy can strengthen the orbital hybridization interaction between Ce-4f and Fe-3d, but it cannot reach the critical point to make the antiferromagnetic stable. The AFM fluctuation still keeps in a value ranging from 2 K to 80 K. The second order paramagnetic-ferromagnetic transition of CeFe1.95In0.05 at TC=230 K is confirmed by Arrott plot analysis. The effective ferromagnetic moment of Fe atoms can be increased by replacing part of the Fe atoms with In atoms in the CeFe2 alloy, which can increase the paramagnetic and effective magnetic moment and the magnetic saturation magnetic moment of the alloy. For a magnetic field change of 0-50 kOe, the maximum value of the magnetic entropy change-△ SM is 3.13 J/(kgK) at 230 K and RCP is 151.3 J/kg, which are higher than the values of Ce0.95Gd0.05Fe2, Ce0.9Gd0.1Fe2, and Ce0.9Ho0.1Fe2 alloys under the same magnetic field. The high self-consistent scaling critical exponents determined by modified Arrott plot and Kouvel-Fisher methods are[=0.3212(8) and =0.9357(9)] and[=0.3304(1) and =0.9249(1)], respectively. The parameter obtained from the critical magnetization isotherm MTC=DH1/ satisfies the Widom scaling relation =1+/. Moreover, the plot of M1/ vs. (H/M) 1/ constructed by the above critical parameters completely complies with the scaling hypothesis. At the same time, the critical parameters of n and obtained by|△ SM| Hn and RCP H(1 + 1/) fitting are 0.6191(8) and 5.0559(1), respectively. In all, non-local effect of spin interaction causes a certain difference between the critical parameters and 3D-Ising model standard values (=0.325, =1.241, n=0.569, and =4.818). But these differences are small, especially for critical parameter , which suggests that the magnetic interaction in CeFe1.95In0.05 alloy is a short-range interaction.