Thermal Decomposition Pathways of Zn_xFe_3–xO₄ Nanoparticles in Different Atmospheres

Abstract

This article shows how initial composition and thermal treatment of nonstoichiometric zinc ferrite nanoparticles (nZFN) can be chosen to adjust the structure and cation distribution and enhance magnetism in the resulting nanoscale material. It also provides insight into new prospects regarding the production and design of nanoscale materials. Investigations were conducted before and after heating of nZFN in an inert atmosphere and a vacuum up to temperature of 1170 °C. Annealing leads to partial reduction of Fe ions, enhanced magnetism, and an increase in the size of the particles independent of the atmosphere. Use of the inert atmosphere delivers a solid solution of magnetite and zinc ferrite with a reduced Zn content in the structure as a result of sublimation of newly formed ZnO and reduction of Fe, and it favors crystallization. A preference for normal-spinel phase and enhancement of magnetic saturation from 20 Am2/kg up to 101 Am2/kg was observed. Vacuum annealing with high probability produces ZnO, Fe3O4, and Fe2O3 multiphase system with signs of amorphization, mainly on the surface. A large fraction of Fe ions is reduced and the volume ratio of Fe3O4 to Fe2O3 increases with heating time. The final solid product from a complete decomposition of ZFN is magnetite.

Low Temperature Chemical Synthesis and Investigation of Cadmium Substituted of Structural Properties of Cobalt Nano Ferrites

“…In cadmium substituted cobalt ferrites, the non-magnetic ion like, Cd 2+ instead of magnetic cobalt ion offer inventive changes in their magnetic properties. The number of fabrication methods have been used for the synthesis of ferrite nanoparticles such as solid state reaction [40], co-precipitation method [41], ceramic method [42], sol-gel method [43], thermal decomposition technique [44], hydrothermal method [45], flash-combustion method [46] etc., The co-precipitation method is a high quality synthetic root for preparation of cobalt ferrite nanoparticles. As indicated by the literature review, some unique properties of co-precipitation method such as high yield with better purity, low cost, production of fine particles with high surface area make it more prominent that others [47][48][49].…”

Synthesis and Investigation of Optical, Magnetic, and Thermoelectric Properties of Li0.5Zr0.5Mg0.5Fe1.5O4Spinel and First-Principles Characterization as an Electrode Material for Li-Ion Batteries

“…The structural design of the spinel oxide material, which is described by tetrahedral (A) and octahedral (B) sublattice sites restricted by oxygen anions, is responsible for the very weak crystal field splitting . The composition of a ferrite spinel oxide is described by (M 1– x Fe x ) A [M x Fe 2– x ] B O 4 , where x is the inversion parameter . Spinel ferrites physical characteristics are influenced by the quantity of x , which in turn depends on the cation sizes, charges, and level of crystal-field stability supplied by octahedral or tetrahedral coordination …”

“…6 The composition of a ferrite spinel oxide is described by (M 1−x Fe x ) A [M x Fe 2−x ] B O 4 , where x is the inversion parameter. 6 Spinel ferrites physical characteristics are influenced by the quantity of x, which in turn depends on the cation sizes, charges, and level of crystal-field stability supplied by octahedral or tetrahedral coordination. 6 The magnetic moments of the cations are described by a ferromagnetic coupling magnetic ions localized in the same sites (i.e., A−A and B−B) and an antiferromagnetic coupling the different sites (i.e., A−B).…”

“…Magnetic nanoparticles are essential elements in numerous cutting-edge technological applications, including MRI contrast agents, hyperthermia, drug delivery, catalysis, ion lithium batteries, and exchange-spring magnet . The structural design of the spinel oxide material, which is described by tetrahedral (A) and octahedral (B) sublattice sites restricted by oxygen anions, is responsible for the very weak crystal field splitting . The composition of a ferrite spinel oxide is described by (M 1– x Fe x ) A [M x Fe 2– x ] B O 4 , where x is the inversion parameter .…”

“…The composition of a ferrite spinel oxide is described by (M 1– x Fe x ) A [M x Fe 2– x ] B O 4 , where x is the inversion parameter . Spinel ferrites physical characteristics are influenced by the quantity of x , which in turn depends on the cation sizes, charges, and level of crystal-field stability supplied by octahedral or tetrahedral coordination …”