Critical phenomena and estimation of the spontaneous magnetization from a mean field analysis of the magnetic entropy change in La0.65Eu0.05Sr0.3Mn0.95Cr0.05O3

[Display omitted] •Nanocrystalline sample La0.65Eu0.05Sr0.3Mn0.95Cr0.05O3 was prepared using the Pechini sol–gel method.•The La0.65Eu0.05Sr0.3Mn0.95Cr0.05O3 exhibits a second order FM–PM phase transition.•The mean-field model describes the critical properties in La0.65Eu0.05Sr0.3Mn0.95Cr0.05O3 perovskite.•Two different methodologies have been used for determining the spontaneous magnetization. We have studied the magnetic and magnetocaloric properties of the La0.65Eu0.05Sr0.3Mn0.95Cr0.05O3 manganite prepared by using a soft chemical method (Pechini method). This compound presents a single magnetic transition from ferromagnetic (FM) to paramagnetic (PM) phase at TC=338K. To investigate the nature of the magnetic phase transition, found to be of second-order, a detailed critical exponent study has been performed by dc-magnetization M (H,T) measurements around the Curie temperature TC. Modified Arrott plot method has been adopted to study the critical behavior of the compound around its transition region. The values deduced for the critical exponents β, γ and δ are close to the theoretical prediction of the mean-field model, indicating that the magnetic interactions are long-range. Moreover, we have investigated the validity and usefulness of the theoretical modeling in our compound La0.65Eu0.05Sr0.3Mn0.95Cr0.05O3 based on the mean-field analysis of the magnetic entropy change (−ΔSM) versus the magnetization data. Results obtained through this approach are compared to those obtained from extrapolation of the Arrott curves. An excellent agreement is found between the experimental (−ΔSM) and the one estimated by Landau theory.