Structural, Magnetic, and Magnetocaloric Properties in Rare Earth Orthochromite (Sm, Nd, and La)CrO3 for Cooling Product

Abstract

Polycrystalline phase of SmCrO3, NdCrO3, and LaCrO3 orthochromites was synthetized with solid-state reaction method. The pure orthorhombic phases with space group Pnma have been confirmed by X-ray diffraction. In addition, the FTIR spectroscopy proved the formation Sm–O, Nd–O, and La–O bonds in SmCrO3, NdCrO3, and LaCrO3 respectively, and Cr–O and Cr–O–Cr bonds in all our samples. The particles morphology and composition results were obtained using the scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). The Quantum Design XL-SQUID magnetometer is used in order to determine the magnetic transition type and transition temperature for each sample. We found that our samples exhibit a transition at 195 K, 65 K, and 35 K for SmCrO3, NdCrO3, and LaCrO3 respectively. The magnetic entropy change (∆Sm), as the key parameter to evaluate the magnetocaloric effect, is calculated. Our samples present a ∆Sm in the range of 0.11 and 0.25 J kg−1 K−1 for an external magnetic field of 5 T.