Room-temperature magnetization reversal and magnetocaloric switching in Fe substituted GdMnO3

Abstract

Room-temperature tunable bipolar magnetization switching and magnetically switchable magnetocaloric phenomena having numerous application potentials are reported in $\mathrm{GdM}{\mathrm{n}}_{1\ensuremath{-}x}\mathrm{F}{\mathrm{e}}_{x}{\mathrm{O}}_{3}$ ($x=0.55$ and 0.60) polycrystalline samples. Substitution of Fe in antiferromagnetic $\mathrm{GdMn}{\mathrm{O}}_{3}$ induces a first-order spin-reorientation transition $({T}_{SR})$, which along with antiferromagnetic ordering transition $({T}_{\mathrm{N}})$ gives rise to anomalies in dielectric spectra, a signature of magnetodielectric effect. Temperature-dependent Raman spectra confirm the spin-phonon coupling which could be the origin of the magnetodielectric effect in the system. Notably, low-field magnetically tunable magnetization reversal is found to appear between ${T}_{\mathrm{SR}}$ and ${T}_{\mathrm{N}}$ in these compounds owing to the competition between single-ion magnetic anisotropy and antisymmetric Dzyaloshinsky-Moriya interaction. Additionally, the $\mathrm{GdM}{\mathrm{n}}_{0.40}\mathrm{F}{\mathrm{e}}_{0.60}{\mathrm{O}}_{3}$ sample reveals the coexistence of magnetically switchable conventional and inverse magnetocaloric effect at 250 and 310 K. The tailoring of these coexisting room-temperature magnetization reversal and magnetocaloric phenomena in a single-phase system suggests a route to design the material suitable for potential applications in electromagnetic and memory devices.