Structural characterization and magnetic properties of superparamagnetic zinc ferrite nanoparticles synthesized by the coprecipitation method

► ZnFe2O4 nanoparticles were synthesized by coprecipitation at temperatures of 20-80 °C. ► Single phase nanoparticles were the mixture of normal and inverse spinel structures. ► The magnetization at 10 kOe was correlated to the crystallite size and inversion parameter. ► The zinc ferrite coprecipitated at 40 °C exhibited the maximum magnetization of 7.3 emu/g.