The effects of synthesis conditions on the magnetic properties of zinc ferrite spinel nanoparticles

Zinc ferrite nanocrystals were synthesized from metal chloride precursors via chemical co-precipitation method, using different synthesis conditions. Characterization measurements including X-ray diffraction (XRD), transmission electron microscopy (TEM) and super conductiong quantum device (SQUID) were used to study the influence of precursor's concentration and reaction time on the crystalline structure, average sizes and magnetic properties of zinc ferrite nanoparticles. The transmission images show spherical, homogenous shape and particle size ranging from 16 to 22 nm. DC magnetization (2-300 K) measurements reveal a superparamagnetic behavior for the ZnFe2O4 samples with a blocking temperature in the range of 18-24 K. Our results demonstrate that magnetic properties of magnetic particles can be largely modified by just changing the reaction condition such as concentration and reaction time, which might be a useful way to design novel magnetic materials.