Co-precipitation synthesizing technique was adopted to prepare manganese doped zinc ferrite nanoparticles with varying concentrations 0.5, 0.6, 0.7. EDX proved the consistency of stoichiometry of compositions in the ferrite samples considered under preparation. XRD patterns authenticated the ferrite phase in the investigating samples. The experimental lattice parameter (8.412–8.438 Å) is increasing and crystallite size (7.6–6.4 nm) appears to be decreasing with substitution of Mn2+. The grain size (1.1 µm) in the sample (x = 0.7) with smaller crystallites (6.4 nm) is found to be bigger than that of remaining compositions (x = 0.5, 0.6). The vibrational frequencies detected in the FTIR spectra also authorized the obtained spinel phase in the current ferrite systems. The elastic moduli illustrate the mechanical strength of ferrite systems which are dependent on interatomic distances. The variation of line width and Lande's g–factor in ESR studies revealed the possibility of core-shell morphology of present ferrite nanoparticles.