Critical behavior near the ferromagnetic to paramagnetic phase transition temperature in polycrystalline La0.5Sm0.1Sr0.4Mn1−xInxO3 (0 ≤ x ≤ 0.1)

In this paper we report on the critical analysis of the La0.5Sm0.1Sr0.4Mn1−xInxO3(0⩽x⩽0.1) manganites near the ferromagnetic-paramagnatic phase transition temperature. Various techniques such as modified Arrott plot, Kouvel-Fisher method and critical isotherm were used to analyze the magnetic-field dependence of magnetization. The Curie temperature (TC) could be tuned over a wide temperature range, from 251 K to 310 K, with varying in content. Though the nature of this transition is found to be of second order, the estimated critical exponents β, γ, and δ obtained for different values of x are close to the theoretically predicted values for the three-dimensional (3D)-Ising interaction model (β = 0.324 ± 0.01, γ = 1.240 ± 0.13 at TC = 310 K for x = 0.00); (β = 0.329 ± 0.04, γ = 1.241 ± 0.001 at TC = 294 K for x = 0.05); (β = 0.332 ± 0.01, γ = 1.250 ± 0.04 at TC = 251 K for x = 0.10) and are very far away from any other known universality class. The critical isotherm M (TC, µ0H) gives δ = 5.02 ± 0.01 for x = 0.00. Thus, the scaling law δ=1+γ/β is fulfilled. The critical exponents obey the single scaling equation of M(μ0H,ε)=εβf±(μ0H/εβ+γ); where f+ for T > TC and f− for T < TC.