Two zinc ferrite nanoparticle materials were prepared by the same method - soft mechanochemical synthesis, but starting from different powder mixtures: (I) Zn(OH)(2)/alpha-Fe2O3 and (2) Zn(OH)(2)/Fe(OH)(3). In both cases a single phase system was obtained after 18 h of milling. The progress of the synthesis was controlled by X-ray diffractometry (XRD), Raman spectroscopy, TEM and magnetic measurements. Analysis of the XRD patterns by Rietveld refinement allowed determination of the cation inversion degree for both obtained single phase ZnFe2O4 samples. The sample obtained from mixture (1) has the cation inversion degree 0.3482 and the sample obtained from mixture (2) 0.400. Magnetization measurements were confirmed that the degrees of the inversion were well estimated. Comparison with published data shows that used method of synthesis gives nano powder samples with extremely high values of saturation magnetizations: sample (1) 78.3 emu g(-1) and sample (2) 91.5 emu g(-1) at T= 4.5 K. (C) 2013 Elsevier Ltd. All rights reserved.