Critical behavior near the paramagnetic to ferromagnetic phase transition temperature in La0.67Sr0.1Ca0.23MnO3 compound

Abstract

The critical behavior of La0.67Sr0.1Ca0.23MnO3 perovskite-manganite was studied around its Curie temperature (TC). Experimental results revealed that this sample underwent a second-order phase transition. Using modified Arrott plot, Kouvel–Fisher method and critical isotherm analysis, the critical parameters (TC, β, γ, and δ) were determined in the two characteristic regions of low- and high-magnetic fields. The estimated critical exponents were close to those expected for three-dimensional Heisenberg class for LSCMO (β = 0.345 ± 0.001, γ = 1.31 ± 0.02 and TC = 294.74 K for μ0H = 0–2 T. However, β = 0.354 ± 0.004, γ = 1.28 ± 0.03 and TC = 294.75 K for μ0H = 3–5 T). These critical exponents fulfill the Widom scaling relation δ = 1 + γ/β, implying the reliability of our values. Based on the critical exponents, the magnetization–field–temperature (M–μ0H–T) data around TC collapses into two curves obeying the single scaling equation M(μ0H, ε) = |ε|β f±(μ0H/|ε|β+γ) where ε = (T − TC)/TC, f+ for T ≻ TC and f− for T ≺ TC. A linear relationship |ΔSMmax(H)|∝Hn was achieved with a local exponent n = 0.58 determined from n = 1+(β − 1)/(β + γ), indicating a short-range FM system.