“…Indeed, in the literature, few studies reported a discussion of the magnetic properties together with the chemical composition obtained by quantitative analytical methods, such as atomic absorption spectroscopy (AAS) or inductively coupled plasma optical emission spectrometry (ICP–OES), or semi-quantitative ones, such as scanning electron microscopy (SEM)–energy dispersive X-ray (EDX) analysis. ,,,,, The crystallite size in the studied samples was found to change as a function of the Co/Mn ratio in the range of 14–22, 16–34, 23–33, , and 3.0–31.0 nm . Some studies focused on a single intermediate chemical composition. ,, Most commonly, a study of the magnetic field ,,,,,,,,,− and/or temperature dependence ,,,,,,, of the magnetization is reported, whereas only rarely an investigation of the interparticle interactions is provided . In one case, the Co/Mn mixed ferrite NPs were used for comparison with bimagnetic core–shell NPs …”