Zinc substitution effect on the structural, spectroscopic and electrical properties of nanocrystalline MnFe2O4 spinel ferrite

Abstract

This paper reports the structural, morphological, spectroscopic, dielectric, ac conductivity, and impedance properties of nanocrystalline Mn 1-x Zn x Fe 2 O 4 . The nanocrystalline Mn–Zn ferrites were synthesized using a solvent-free combustion reaction method. The structural analysis using X-ray diffraction (XRD) pattern reveals the single-phase of all the samples and the Rietveld refined XRD patterns confirmed the cubic-spinel structure. The calculated crystallite size values increase from 8.5 nm to 19.6 nm with the Zn concentration. The surface morphological analysis using field emission scanning electron microscopy and the transmission electron microscopy confirms the nano size of the prepared ferrites. X-ray photoelectron spectroscopy was used to study the ionic state of the atoms present in the samples. Further, the high-resolution Mn 2p, Zn 2p, Fe 2p, and O 1s spectra of Mn 1-x Zn x Fe 2 O 4 does not result in the appearance of new peaks with Zn content, indicating that the Zn substitution does not change the ionic state of Mn, Zn, Fe, and O present in nanocrystalline Mn 1-x Zn x Fe 2 O 4 . The investigated electrical properties show that the dielectric constant, tan δ and ac conductivity gradually decrease with increasing Zn substitution and the sample Mn 0 · 2 Zn 0 · 8 Fe 2 O 4 has the lowest value of conductivity at 303 K. The ac conductivity measured at different temperatures shows the semiconducting nature of the ferrites. The impedance spectra analysis shows that the contribution of grain boundary is higher compared with the grain to the resistance. The obtained results suggest that the Zn substituted manganese ferrite nanoparticles can act as a promising candidate for high-frequency electronic devices applications.

Correlation between Magnetic and Dielectric Response of CoFe2O4:Li1+/Zn2+ Nanopowders Having Improved Structural and Morphological Properties

“…At first the increase for sample x = 0.1 (ε′ = 5.89) could be attributed to the incorporation of Zn ions at tetrahedral site that pushes more Fe 3+ towards octahedral site. Thus, hopping mechanism with oxygen vacancy and stress increases which leads to more production of Fe 2+ ions in octahedral sites, which is in accordance with previous reports [ 71 ]. However, a decreasing trend is followed with dopants concentration and strain as well.…”

Effects of Strontium on the Structural, Optical, and Microwave Dielectric Properties of Ba2Ti9O20 Ceramics Synthesized by a Mixed Oxide Route

“…The AC conductivity increases slowly at low frequency but abruptly increases at high frequency. These changes in AC conductivity may occur due to the hopping charge carriers and structure of the grains as well. , It is observed that the conductivity (σ AC ) varies with an increase in frequency. The trapping and fluctuations of conductivity may be due to the increase in temperature of the ceramic samples from the thermal activation energy.…”

The Effect of Ca Dopant on the Electrical and Dielectric Properties of BaTi4O9 Sintered Ceramics

“…At lower frequencies, the resistive nature of grain boundaries becomes more complicated, resulting in a low conductivity value being observed [ 21 ]. The high conductive structure of grains becomes highly active at higher frequencies, resulting in increased charge carrier hopping between the ions and increased conductivity [ 22 ]. The net conductivity of ceramics can be found using Jonsher’s Power Law (JPL).…”