For instance, a broad range of MnxFe3-xO4 MNPs (0 ≤ x <1) prepared by the co-precipitation method showed a monotone increase of lattice parameters and heating capacity as the Mn 2+ content increased, although these results could not be exclusively attributed to the Mn 2+ content due to the size dispersion between samples . Conversely, other authors did not find a correlation between Mn 2+ content and their magnetic properties or reported that the net Ms values did not follow an increasing tendency as Mn 2+ content increased , even when a correlation between crystallite size and Mn 2+ content was observed. One of the major challenges to study how the composition of MnxFe3-xO4 MNPs impacts the structural-magnetic properties is to maintain similar average size, shape, and monodispersity across all samples, a fact that has been frequently overlooked. In an attempt to exclusively correlate Mn 2+ content and Ms values, computational modelling was carried out, demonstrating a positive correlation between Mn 2+ content and Ms . However, the experimental data showed inverse results, which were attributed to a decrease in the crystallite and magnetic diameters promoted by the incorporation of Mn 2+ . Such dissimilarities across works are also reflected in the optimal conditions to effectively dissipate heat under an alternating magnetic field (AMF) and/or to behave as contrast agents. For instance, similar Specific Loss Power (SLP) under an AMF was obtained for samples with a very distinctive composition , whereas similar compositions produced big differences in terms of heat production depending on their internal structural defects . Other authors found highly variable the optimal Mn 2+ content needed to efficiently dissipate heat under similar AMF conditions . Similarly, different works reported divergent results related to the impact of the composition on the contrast ability. Low Mn 2+ contents were associated with improved positive contrast efficiency, while high levels drove ferrites onto dual-mode magnetic resonance imaging agents . However, other reports showed improved negative contrast ability when composition reached x = 0.43, while a complete deterioration was found for higher doping levels .