Influence of the starting powders on the synthesis of nickel ferrite

Abstract

The thermal decomposition of freeze-dried nickel(II)-iron(III) formate was investigated by means of DTA, TG, mass spectrometry and X-ray powder diffractometry. For the preparation of homogeneous freeze-dried nickel(II)-iron(III) formate precursors, a rigorous control of nickel ion concentration in the precursor solution was required. The decomposition of the reactive nickel(II)-iron(III) formate does not only reflect aspects of single formates, but also an interaction between components which lowers the decomposition temperature. Crystalline nickel ferrite powders were obtained at 600-800°C. This temperature is quite lower than 1100°C employed for the ceramic method. In the presence of air, the regeneration of nickel ferrite from the taenite phase (γNi,Fe) is accomplished at 800°C. This temperature is also 300°C below the temperature employed when the mixtures NiO:α-Fe 2 O 3 or Ni:2Fe are the starting powders. The main reason for the high reactivity of the freeze-dried formates and the taenite alloy is the large homogeneity of these precursors.

Precursor-Driven Catalytic Performances of Al2O3-Supported Earth-Abundant Ni Catalysts in the Hydrogenation of Levulinic Acid and Hydroxymethylfurfural into Added-Value Chemicals

“…In the next step, at a temperature above 400 °C, Ni is probably reoxidized. It has been shown that the decomposition of NiF in air at temperatures above 300 °C leads to the formation of a mixture of nickel oxide and metallic nickel [30,31]. The NiN (Figure 1c) decomposes in several steps with a total weight loss of approx.…”

PANI/Zn‐Cu ferrite polymer composites as free‐standing high dielectric materials

“…Out of all inorganic fillers, ferrite fillers are more crucial due to their stable crystal structure, good magnetic properties, high electrical properties, and the spinel ferrites are widely used in electronic devices, magnetic materials based on them have attracted a lot of attention. [15][16][17][18][19] Because of lowdimensional electrical system applications, nanoscopic sized filler particles are in polymer matrix, such a combination exhibits improved electrical characteristics. Because of their spinel structure, ferrites are a prominent filler material used by scientists for improving the electrical features of pure polymers.…”

“…The main advantage of inorganic filling is that it is nontoxic. Out of all inorganic fillers, ferrite fillers are more crucial due to their stable crystal structure, good magnetic properties, high electrical properties, and the spinel ferrites are widely used in electronic devices, magnetic materials based on them have attracted a lot of attention 15–19 . Because of low‐dimensional electrical system applications, nanoscopic sized filler particles are in polymer matrix, such a combination exhibits improved electrical characteristics.…”