Giant magnetocaloric effect in Fe-doped rare earth orthochromite GdCr0.5Fe0.5O3

Abstract

In this manuscript, we present investigations into the magnetic and magnetocaloric properties of the Fe-doped orthochromite system GdCr_0.5Fe_0.5O₃, along with its structural, electronic and thermal properties. Manifestations of orbital-mediated electron–phonon coupling, the charge transfer mechanism and exchange splitting can clearly be observed in the acquired Raman and core-level X-ray photoemission spectra. Additionally, Fe substitution enhances Cr³⁺/Fe³⁺ spin canting, thereby strengthening the weak ferromagnetic component over the paramagnetic moment of Gd³⁺, resulting in a suppression of temperature-induced magnetization reversal in the Fe-doped system as compared to the parent GdCrO₃. A maximum magnetic entropy change (−ΔS^max_m) of 44.86 J kg⁻¹ K⁻¹, adiabatic temperature change (ΔT^max_ad) of 15.14 K and relative cooling power (RCP^max) of ∼691.81 J kg⁻¹ for a magnetic field variation of 9 T at cryogenic temperatures were obtained from the temperature-dependent magnetization and heat capacity measurements. These observed giant magnetocaloric effect parameters make this system a promising competitor in the field of magnetic refrigeration technology for cooling applications at cryogenic temperatures.