Structural, magnetic, magnetocaloric properties and the formation of nano-size Griffiths-like clusters in La0.8Ba0.1Ca0.1Mn0.8Co0.2O3 manganites

Abstract

In this work, the polycrystalline La0.8Ba0.1Ca0.1Mn0.8Co0.2O3 was prepared by polymerization complex sol–gel method. The crystallographic study indicates that our sample crystallizes in the orthorhombic structure with Pbnm space group, at room temperature. The magnetic properties of this compound are discussed in detail, based on magnetization and the inverse of susceptibility, over a wide temperature range (T = 0–300 K). Magnetic data, in an applied magnetic field of 0.05 T, show that our sample exhibits a paramagnetic (PM) – ferromagnetic (FM) transition with decreasing temperature. The dependence of the inverse of magnetic susceptibility on temperature above Curie temperature, confirms the presence of Griffiths phase (GP), which proves the existence of FM clusters in the PM region. The field dependence of magnetocaloric properties of La0.8Ba0.1Ca0.1Mn0.8Co0.2O3 sample, with second phase transition material, was investigated. The magnetic entropy change reaches a maximum of 3.1 J/kg.K with a relative cooling power (RCP) of 186 J/kg at 174 K for a 5 T field change. Our results are interesting and indicate that this material can be a suitable candidate in magnetic refrigeration.