Critical behavior at high magnetic fields in LaPr(Ca,Sr)MnO manganites

Abstract

In this work, we demonstrate that La0.225Pr0.4(Ca1−xSrx)0.375MnO3 manganites with 0≤x≤0.10, exhibit a discontinuous first order ferromagnetic-paramagnetic transition at temperatures ~ 230–240 K, which evolves to a continuous second order ferromagnetic-paramagnetic transition according to the intensity of the applied magnetic field. Under high magnetic fields and through a magnetization scaling analysis, we have determined the critical exponents of the sample with x = 0.05 - β = 0.15, γ = 0.77, and δ = 6.24, and x = 0.10 - β = 0.165, γ = 0.62, and δ = 4.69. The exponents values obey the scaling laws but do not belong to any existing universality class. This analysis of critical behavior can be used to predict the magnetic entropy change under high magnetic fields.