Wet Chemical Synthesis of Cubic Spinel Ferrites: A Review Addressing Phase Formation Behavior and Nanostructuring

Abstract

Spinel ferrites, an important class of complex oxides, are imperative worldwide for their well-known magnetic, electrical, optical, catalytic properties, which led tem to be useful in various applications. These can be prepared through various solid state, physical, and wet chemical methods. One difficulty associated with the preparation of complex compositions of spinel ferrite (e.g., AB 2 O 4 where A and B are two different metal cations with +2 and +3 valence states, respectively) is the fact that often individual metal oxides are obtained as impurities with the desired composition. Mostly, the spinel ferrites crystallize into cubic phase, which makes these isotropic oxides difficult to grow in 1D structures like other anisotropic oxides such as hexagonal zinc oxide and tetragonal titania. Existing reports have mostly overlooked the aforementioned challenges for the synthesis of spinel ferrites. Viewing in the same line, in the present Review, we have reviewed different wet chemical approaches for the synthesis of spinel ferrites and made an attempt to correlate the phase formation behavior, composition, and morphology with the synthesis procedure. In addition, the procedures and mechanisms for the synthesis of phase-pure 1D spinel ferrites are also described. This Review offers comprehensive insight for researchers keen on delving into the synthesis and diverse applications of cubic spinel ferrites.