Critical Behavior in the La0.6Ca0.4MnO3 Perovskite Manganite

Polycrystalline La_0.6Ca_0.4MnO₃ sample has been prepared by sol-gel method and has an orthorhombic perovskite structure with Pnma space group. Close to magnetic temperature transition, the order transition and the critical behavior are investigated by dc magnetization measurements. Using various techniques such as modified Arrott plots, Kouvel–Fisher method, and Widom scaling relation, the values of T _C ferromagnetic transition temperature, as well as the β, γ, and δ critical exponents, are estimated. The values of critical exponents, derived from the magnetic data, yield 0356 ≤ β ≤ 0382, 1273 ≤ γ ≤ 1291, and 4.37 ≤ δ ≤ 457. The critical exponents reported in this study obey the Widom scaling relation δ = 1 + γ/ β, implying that the obtained values of β and γ are reliable. We conclude that La_0.6Ca_0.4MnO₃ belongs to the 3D-Heisenberg class with short-range interaction.