| Summary: | Rare-earth chromites have been envisioned to replace gas-based refrigeration technology because of their promising magnetocaloric properties at low temperatures, especially in the liquid helium temperature range. Here, we report the low-temperature magnetic and magnetocaloric properties of Gd<sub>0.5</sub>Er<sub>0.5</sub>Cr<sub>1−x</sub>Mn<sub>x</sub>O<sub>3</sub> (<i>x</i> = 0, 0.1, 0.2, 0.3, 0.4 and 0.5) rare-earth orthochromites. The Néel transition temperature (<i>T<sub>N</sub></i>) was suppressed from 144 K for Gd<sub>0.5</sub>Er<sub>0.5</sub>CrO<sub>3</sub> to 66 K for the Gd<sub>0.5</sub>Er<sub>0.5</sub>Cr<sub>0.5</sub>Mn<sub>0.5</sub>O<sub>3</sub> compound. Furthermore, magnetization reversal was observed in the magnetization versus temperature behavior of the Gd<sub>0.5</sub>Er<sub>0.5</sub>Cr<sub>0.6</sub>Mn<sub>0.4</sub>O<sub>3</sub> and Gd<sub>0.5</sub>Er<sub>0.5</sub>Cr<sub>0.5</sub>Mn<sub>0.5</sub>O<sub>3</sub> compounds at 100 Oe applied magnetic field. The magnetic entropy change (−∆S) value varied from 16.74 J/kg-K to 7.46 J/kg-K, whereas the relative cooling power (RCP) ranged from 375.94 J/kg to 220.22 J/kg with a Mn ion concentration at 5 T field and around 7.5 K temperature. The experimental results were substantiated by a theoretical model. The present values of the magnetocaloric effect are higher than those of many undoped chromites, manganites and molecular magnets in the liquid helium temperature range.
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