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

One-Step Synthesis of Long Term Stable Superparamagnetic Colloid of Zinc Ferrite Nanorods in Water

“…The water colloidal stability of nanostructures of various shapes and sizes constitutes the most important challenge to achieve useful systems for biomedical and industry applications. Preparation of colloidal stable dispersion is usually performed in two stages: Formation of nanoparticles, e.g., zinc ferrite ZnFe 2 O 4 , by means of e.g., micro-emulsion [23], co-precipitation method [24,25], milling [26], sol-gel method [27], hydrothermal [28], solvothermal [29], spray pyrolysis [30] or thermal decomposition method [31],Further stabilisation/dispersion of nanoparticles in various non-polar or polar fluids [32,33]. …”

Synthesis and characterization of nanocrystalline zinc ferrite spinel powders by homogeneous precipitation method

“…Different processes such as hydrothermal [20], solvothermal [21], thermal decomposition [22], solid-state reaction [23], reverse micelle [24], micro-emulsion [25], sonochemical [26,27], spray pyrolysis [28], combustion [29], mechanochemical [30], citrate precursor [31], electrodeposition [32] and sol-gel [33,34] methods have been used to synthesize nanocrystalline ZnFe 2 O 4 . However, these techniques are difficult to develop in large-scale industrial applications because they are expensive, complicated, require sophisticated apparatus, high reaction temperatures, long production time, toxic reagents and producing byproducts which are harmful to the environment.…”

Characterisation of Mn0.63Zn0.37Fe2O4 powders after intensive milling and subsequent thermal treatment

“…Thus remaining manganese ions are reduced from the Mn 3+ to the Mn 2+ oxidation state. Oxidation of Mn 2+ ions is known to proceed most rapidly at 900-1000 o C, while the optimal temperature to produce Mn-Zn ferrites lies in the temperature range of 1000 o C to 1200 o C. Specific cooling modes, including oxygen control in the furnace chamber, are typically applied to avoid Mn 2+ oxidation and to produce ferrites with proper functional features [13]. In air atmosphere reformation of Mn-Zn ferrites is followed by oxygen release and expansion noted on the dilatometric device for the powders activated 30 and 60 minutes that originates from an abrupt oxygen release at 1300 o C. The combination of milling and sintering conditions is leading to the shortening of diffusion paths and oxygen release hindering that results in swelling of the particular specimens.…”