Structure and magnetic properties of manganese–zinc-ferrites prepared by spray pyrolysis method

• A single-phase Zn0.5Mn0.5Fe2O4 spinel ferrite is prepared by spray pyrolysis.
• A uniform distribution of Mn and Zn over the Zn0.5Mn0.5Fe2O4 lattice was achieved.
• The ferrite spheres (0.15–1.6 mkm) consist of small grains with a size of 4–12 nm.
• The prepared ferrite is superparamagnetic with the Curie point of 375 ÷ 380 K.

A spray pyrolysis of a water solution of iron, manganese and iron nitrates is applied to prepare Zn0.5Mn0.5Fe2O4 single-phase ferrite with a spinel-type structure. The samples are characterized by means of differential scanning calorimetry, scanning and transmission electron microscopy, X-ray diffraction, infrared and 57Fe Mössbauer spectroscopy. The mass magnetization σ and the magnetic susceptibility 1/χ of the ferrites are measured as a function of temperature over the range of 78–728 K. The obtained sample contains nanoparticles with an average diameter d ∼7 nm possessing MnxZnyFe3−(x+y)O4 spinel-type structure with a uniform distribution of manganese and zinc atoms over the ferrite lattice. The Curie temperature is determined to be 375 ÷ 380 K.

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