Magnetization reversal study of Ni_4-xZn_xNb₂O₉ compounds using Monte Carlo simulations

The magnetization reversal (MR) of the layered Ni4-x ZnxNb2O9 ferrimagnetic compounds, with x=0,0.25,0.50 and 0.75, is studied in this work using Monte Carlo (MC) simulations and mean field (MF) calculations. First, we analyze the parent compound to set the parameters of our simulations; testing together MC simulations, MF calculations, and MR experiments reported by Bolletta et al (2022 J. Appl. Phys. 132 153901). Then using two different approaches we fit the MR curves of the series of compounds finding a quite good agreement between MC simulations and the experiments. According to these results, Zn substitutions change the relative contribution to the magnetization of the different layers. Here we present two possible hypotheses to explain this effect; one involving a heterogeneous distribution of Zn2+ among the layers, and the other related to distortions of the NiO6 octahedra.