The Inverse and Conventional Magnetocaloric Effects in Ni0.4Cu0.2Zn0.4Fe2-xDyxO4 Nanoferrites Over an Extraordinary Temperature Range

Abstract

AbstractThe magnetocaloric effect (MCE) of Ni0.4Cu0.2Zn0.4Fe2-xDyxO4 (x = 0.02, 0.03, and 0.04) nanoferrites is simulated using a phenomenological model. The analysis indicates that the MCE of Ni0.4Cu0.2Zn0.4Fe2-xDyxO4 nanoferrites is strongly influenced by Dy content in both conventional and inverse MCE. For conventional MCE, the full-width at half-maximum ($$\delta {\text{T}}_{{{\text{FWHM}}}}$$ δ T FWHM ) has significant values, ranging between 200 K and 258 K for Ni0.4Cu0.2Zn0.4Fe2-xDyxO4 nanoferrites. However, for inverse MCE, $$\delta {\text{T}}_{{{\text{FWHM}}}}$$ δ T FWHM ranges between 25 and 55 K. The MCE of the Ni0.4Cu0.2Zn0.4Fe2-xDyxO4 system covers an extensive temperature range and is a particularly interesting prospect for nitrogen and hydrogen liquefaction.