Exploring the structural, magnetic, magnetocaloric and magnetoresistance behaviour of La2/3Sr1/3Mn(1-x)CrxO3 with varying Cr content

Abstract

Chromium-substituted La_2/3Sr_1/3MnO₃ ceramics were prepared using the conventional solid state synthesis route. Rietveld refinement was performed for structural analysis, revealing rhombohedral symmetry and a uniform perovskite phase. The analysis indicates a systematic decrease in unit cell volume and lattice parameter with increasing Cr content. Temperature dependent magnetization data show a well-defined transition exhibiting spin/cluster glass behavior. La_2/3Sr_1/3Mn_0.9Cr_0.1O₃ shows a magnetocaloric effect of 2.11 J kg⁻¹ K⁻¹ at 316 K under a 5 T magnetic field. A comprehensive analysis of field-dependent magnetization, Arrott plots, and magnetic entropy change (−ΔS_M) for x = 0.1 and x = 0.33 compositions highlights their second-order magnetic phase transitions. Resistivity analysis reveals that Cr substitution effectively enhances magnetoresistance at room temperature, with values of ∼12.5 % for x = 0.03 and ∼19 % for x = 0.1. These results underscore the potential of these compositions for applications requiring tunable magnetoresistance across a broad temperature range.