Januar Widakdo

Thermal annealing tailors crystallinity and magnetism in silica coated Ni-Zn ferrite (SiO2@NiZnFe2O4) nanoparticles

Introduction

Thermal annealing tailors crystallinity and magnetism in silica coated ni-zn ferrite (sio2@niznfe2o4) nanoparticles. Explore how thermal annealing enhances crystallinity and magnetism in Ni-Zn ferrite nanoparticles, optimizing their structural and magnetic properties for electronic device applications.

Abstract

Ni0.5Zn0.5Fe2O4 nanoparticles were synthesized using a co-precipitation method followed by annealing at different temperatures to investigate their structural, morphological, and magnetic properties. X-ray diffraction (XRD) confirmed the formation of a single-phase spinel structure, with increased crystallinity and grain growth observed at higher annealing temperatures. Transmission electron microscopy (TEM) and selected area electron diffraction (SAED) further revealed a transition from small, aggregated nanoparticles to well-defined crystalline grains. Magnetic hysteresis measurements demonstrated a significant enhancement in saturation magnetization (Ms) and coercivity (Hc) with increasing temperature, reaching up to 55.15 emu/g and 253.23 Oe, respectively, at 800 °C. These improvements are attributed to reduced surface spin disorder and increased magnetic domain alignment due to grain growth. The results underscore the importance of annealing temperature in tailoring the magnetic behavior and structural properties of Ni–Zn ferrite nanoparticles for potential applications in magnetic and electronic devices.

Review

This manuscript presents a focused and well-executed study on tailoring the structural and magnetic properties of Ni-Zn ferrite nanoparticles through systematic thermal annealing. The authors employed a standard co-precipitation method followed by varying annealing temperatures to synthesize Ni$_{0.5}$Zn$_{0.5}$Fe$_{2}$O$_{4}$ nanoparticles, and meticulously characterized them using a suite of techniques including XRD, TEM, SAED, and magnetic hysteresis measurements. The clear objective of investigating the impact of annealing on crystallinity, grain growth, and magnetic behavior is effectively addressed, making the study's aim transparent and its methodology sound based on the provided abstract. The findings are compelling and clearly demonstrate the significant influence of annealing temperature. The abstract highlights a direct correlation between higher annealing temperatures and enhanced crystallinity, increased grain size, and subsequently improved magnetic properties, notably saturation magnetization (Ms) reaching 55.15 emu/g and coercivity (Hc) at 253.23 Oe at 800 °C. The proposed mechanisms—reduction in surface spin disorder and better magnetic domain alignment due to grain growth—provide a plausible explanation for the observed magnetic enhancements. These results are valuable for the field, underscoring the critical role of post-synthesis thermal treatment in optimizing the functional properties of ferrite nanoparticles for potential applications in magnetic and electronic devices. While the study appears comprehensive in its characterization and provides clear insights into the effect of annealing, a notable discrepancy exists between the title and the abstract. The title explicitly states "silica coated Ni-Zn ferrite (SiO2@NiZnFe2O4) nanoparticles," yet the abstract details the synthesis and characterization solely of "Ni$_{0.5}$Zn$_{0.5}$Fe$_{2}$O$_{4}$ nanoparticles" without any mention of the SiO$_{2}$ coating, its method of application, or its potential influence on the properties. This omission needs to be addressed for clarity; either the abstract should integrate the role of the SiO$_{2}$ coating, or the title should be adjusted if the coating was not a primary focus of this specific study. Despite this, the work represents a solid contribution to understanding the synthesis-property relationships in Ni-Zn ferrites and is highly relevant to materials science and engineering.

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