The cation inversion and magnetization in nanopowder zinc ferrite obtained by soft mechanochemical processing

摘要

Two zinc ferrite nanoparticle materials were prepared by the same method - soft mechanochemical synthesis, but starting from different powder mixtures: (1) Zn(0H)_2/α-Fe_2O_3 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 ZnFe_2O_4 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=4.5K.