Synthesis of Spinel CoFe₂O₄ Via the Co‐Precipitation Method Using Tetraalkyl Ammonium Hydroxides as Precipitating Agents

Abstract

Spinel Cobalt ferrites were synthesized by the co‐precipitation method using tetramethyl‐, tetraethyl‐, and tetrabutyl ammonium hydroxide as precipitating agents. The products were characterized by X‐ray diffraction, scanning electron microscopy, atomic absorption spectroscopy, thermogravimetric analysis, and low‐temperature nitrogen adsorption measurements. The influence of the length of the carbon chain of the precipitating agent on the progressive development of the spinel structure has been investigated as a function of thermal decomposition temperature. The degree of crystallization depends on the thermal decomposition temperature, and also on the type of precipitating agent used to form the precursor. Tetrabutyl ammonium hydroxide is the weakest base with the highest molecular weight among the three precipitating agents. An increase in the size of the tetraalkyl ammonium cation reduces the crystallite size and lattice parameter of cobalt ferrite spinel. It also appears to reduce the degree of particle aggregation significantly.

Composites of Laponite and Cu–Mn Hopcalite-Related Mixed Oxides Prepared from Inverse Microemulsions as Catalysts for Total Oxidation of Toluene

“…The effect was attributed to the higher content of the less ordered/poorly crystalline spinel phase in the materials prepared with TBAOH, as opposed to those synthesized with NaOH. The uniqueness of the nanocrystalline oxide phases obtained from the precursors precipitated with tetraalkylammonium hydroxides, in particular, their low crystallinity, has also been observed by others [38,39]. The schematic models of both types of composites are shown in Figure 7.…”

The role of cobalt ferrite magnetic nanoparticles in medical science

“…Cobalt ferrite belongs to a family of AB 2 O 4 -type spinel ferrites (where A is a divalent metal) and has been studied extensively because of its interesting magnetic properties [20]. From the crystallography viewpoint, in the Co-ferrite A sites are occupied by Fe 3+ ions, while B sites are equally populated by Co 2+ and Fe 3+ ions.…”

Preparation of Cobalt Ferrite Thick Films and Their Magnetic and Electrical Properties

“…[4][5][6] However, the detailed reports on cobalt ferrite, which is one of the potential candidates for magnetic and magneto-optical recording media, 7,8 have not drawn enough interest so far. Much attention has been paid on the synthesis of nanostructured cobalt ferrite particles as well as bulk ceramics or thin films [9][10][11][12][13][14] and characterizations of their magnetic properties. As for their dielectric properties, which can provide important information on the behavior of localized electric charge carriers, giving rise to a better understanding of the mechanism of dielectric polarization, they have attracted little attention except for few reports on nanostructured Co Fe 2 O 4 powder.…”