Improved Electrical Properties of Strontium Hexaferrite Nanoparticles by Co²⁺ Substitutions

Abstract

In this work, the sol–gel route was employed to synthesize a series of Co2+-substituted strontium hexaferrite nanoparticles (Sr1–x Co x Fe12O19, x = 0.0–0.50) to study the effect of cobalt ions doping on the magnetic, electrical, and structural properties of the nanoparticles. The structural analysis of the synthesized nanoparticles, performed by X-ray diffraction, showed the formation of a hexagonal structure having no secondary phases. The morphological analysis, performed through scanning electron microscopy, revealed spherical shaped nanoparticles with uniform distribution. Fourier transform infrared spectra demonstrated two consistent absorption bands indicating the intrinsic stretching vibrations around 600 and 400 cm–1 for tetrahedral and octahedral sites, respectively. It was observed through VSM that with cobalt addition, the saturation magnetization increased and the coercivity decreased. Also, a typical decreasing trend of DC electrical resistivity with increasing temperature measured by a two-probe method confirmed the semiconducting behavior of the synthesized samples. An impedance analyzer was used for the dielectric measurements at room temperature against the alternating frequency range of 250 Hz to 5 MHz, and it was found that the dielectric constant decreased with the increase in cobalt content, suggesting that the doped nanomaterials can be used for microwave absorption, electronics, telecommunication, and other high-frequency applications.

Experimental and Theoretical Realization of Morphology and Frequency Tuned Charge Transport Dynamics in Co-Zn Doped SrM Hexaferrite: Electrical, Impedance and Relaxation Realm

“…Meanwhile, the band shifts towards higher frequency due to a reduction in bond length. Hence, the FTIR findings are in good agreement with the XRD data, as shown by Gulbadan S. and Rehman M. 25,26 For all samples, the absorption peak around 580-590 cm −1 is distinguished which may be associated with the Sr-O stretching vibration band. 27 Similar results were observed in Co substituted M-type barium and strontium hexaferrite, respectively.…”

“…27 Similar results were observed in Co substituted M-type barium and strontium hexaferrite, respectively. 26,28 SEM analysis.-Figure 4 illustrates micrographs of the MF1, MF2, and MF3 samples, showcasing structures in the micrometer range composed of agglomerations of several nanometer-sized particles. In all samples, the micrographs reveal platelet-shaped hexagonal particles with distinct geometric shapes.…”

Tuning the magnetic properties of hard–soft Ba0.5Sr0.5Fe10Al2O19 and Ni0.1Co0.9Fe2O4 nanocomposites via one pot sol–gel auto combustion method for permanent magnet applications

“…The stretching vibrations in ferrites are due to metal ions located in tetrahedral and octahedral crystallographic sites that range from 400 to 600 cm −1 [27]. The absorption band seen at lower wave numbers, about 400 cm −1 , may be attributed to the inherent stretching vibration of metal-oxygen (M-O) bonds at an octahedral site [28]. At the higher wave number ranging around 600 cm −1 is the intrinsic stretching vibration from the tetrahedral site [29].…”

Nanoparticles Based on Prussian Blue for Biosensor Applications: A Review

“…4 The sensor can be miniaturized and integrated into various intelligent application devices, such as smartphones and smartwatches, for clinical care, 5 food analysis, 6 agricultural 7 and environmental monitoring, 8 and the in vivo detection of various diseases 9 and physical conditions. 10 With the rapid development of nanotechnology, nanomaterials with unique optical, 11,12 electrical, 13 and catalytic properties, 14 and biocompatibility 15 have been developed. The application of nanomaterials can significantly improve the response performance of biosensors.…”