Microstructural changes and effect of variation of lattice strain on positron annihilation lifetime parameters of zinc ferrite nanocomposites prepared by high enegy ball-milling

Abstract

Zn-ferrite nanoparticles were synthesized at room temperature by mechanical alloying the stoichiometric (1:1 mol%) mixture of ZnO and α-Fe 2 O 3 powder under open air. Formation of both normal and inverse spinel ferrite phases was noticed after 30 minutes and 2.5 hours ball milling respectively and the content of inverse spinel phase increased with increasing milling time. The phase transformation kinetics towards formation of ferrite phases and microstructure characterization of ball milled ZnFe 2 O 4 phases was primarily investigated by X-ray powder diffraction pattern analysis. The relative phase abundances of different phases, crystallite size, r.m.s. strain, lattice parameter change etc. were estimated from the Rietveld powder structure refinement analysis of XRD data. Positron annihilation lifetime spectra of all ball milled samples were deconvoluted with three lifetime parameters and their variation with milling time duration was explained with microstructural changes and formation of different phases with increase of milling time duration.

Preparation of magnetically recyclable ZnFe2O4 nanoparticles by easy single‐step co‐precipitation method and their catalytic performance in the synthesis of 2‐aminothiophenes

“…Among them, ZnFe 2 O 4 has received much attention due to its potential uses in optical and electrical devices, as adsorbent material for hot‐gas desulfurization, in catalytic transformations, and in biomedicine . ZnFe 2 O 4 has been fabricated using different procedures, such as co‐precipitation, solid‐state reaction, sol–gel, glycine combustion method, microwave‐assisted solvothermal and solvothermal synthesis, combustion reaction using urea as reducing agent, high energy ball‐milling, phase chemical reaction, polyethylene glycol‐assisted route, thermal plasma synthesis, one‐step solid microwave combustion method, and synthesis in supercritical fluids . Zinc ferrite can be separated from reaction mixtures by applying an external magnet and could be reused in further reactions …”

Effect of Milling Time on Co<SUB>0.5</SUB>Zn<SUB>0.5</SUB>Fe<SUB>2</SUB>O<SUB>4</SUB> Microstructure and Particles Size Evolution via the Mechanical Alloying Method

“…There is a significant reduction of the ZnO phase to a large extent compared to the CoO and Fe 2 O 3 phases after 1 hour of milling which subsequently vanished after 4 hours of milling. It shows that the ZnO phase is much more prone to deformation fault as all the reflections are sufficiently broadened in comparison to the other two phases [8]. Conclusion can be drawn that the rate of solid-state diffusion of ZnO into Fe 2 O 3 lattice is higher than that of CoO.…”

“…The chemicals were mixed with chosen molar ratio of 1:0.5:0.5. High energy milling was carried out in a SPEX 8000D shaker mill in ambient atmosphere for 1,4,8,12, and 17 hours. The ball-to-powder mass-charge ratio (BPR) was approximately 10:1.…”

Tunable Magnetic and Electrical Properties of Cobalt and Zinc Ferrites CO1-XZnXFe2O4 Synthesized by Combustion Route

“…Spinel ferrites such as zinc ferrites, have great potential for applications in multi-functional devices such as magnetic field sensors, memory devices 1,2 , electric field converters in microwave region, electromagnetic wave filters, phase shifters, waveguides, oscillators and others 3 . Nanopowders of ferrites exhibits special magnetics and electrical properties, that are sensible to structure, synthesis method, particle size and cation distribution between A and B sites 4 .…”