Investigating the structural, magnetic, magnetocaloric and critical behavior of Mg0.35Zn0.65Fe2O4 ferrite

In this study, we successfully prepared the Mg0.35Zn0.65Fe2O4 ferrite sample via standard solid-phase reaction and comprehensive studied its structure, magnetism, magnetocaloric effect and critical behavior. The XRD data refined by Rietveld technology confirms that the sample had a pure phase spinel structure. We conducted a magnetic study on the sample using SQUID and indicated that the sample' ferromagnetic curie temperature T-c = 295 K, the paramagnetic curie temperature T-P = 330 K, and the saturation magnetization can reach 125.41emu/g at an ultra-low temperature of 5 K. We tested the initial magnetization curve near the phase transition temperature (T-c) from ferromagnetic (FM) to paramagnetic states (PM) and produced an Arrott plot that confirmed the presence of a secondary phase transition. The sample' maximum magnetic entropy change vertical bar Delta S-M(max)vertical bar was 1.642 J/kg K and relative cooling power RCP was 185.2 J/kg in the external magnetic field H = 50 kOe. The critical parameter beta, gamma, delta, and TP were calculated using a Modified Arrott plot (MAP), Kouvel-Fisher (KF) plot and critical isotherm (CI) methods to study the type of magnetic order in the ferromagnetic state that corresponded to the magnetic state equation and mean field model. By analyzing the critical parameters, we obtained the ferromagnetic exchange integral constant J(r) similar to r(-4.8498), which was between the 3D Heisenberg model and mean field models and very close to the mean field model, confirming that the long-range and short-range ferromagnetic orderly interactions coexisted with interaction phases and the long-range ferromagnetic orderly interaction dominates.

Automated summary

In this study, a Mg0.35Zn0.65Fe2O4 ferrite sample was successfully prepared and comprehensive studies on its structure, magnetism, magnetocaloric effect, and critical behavior were conducted. The sample exhibited ferromagnetic and paramagnetic phases at temperatures Tc = 295K and Tp = 330K, respectively. The sample showed good magnetic properties under an external magnetic field H = 50 kOe.