Effect of La3+/Cu2+ and La3/Ni2+ substitution on the synthesis, magnetic and dielectric properties of M−type Sr1-xLaxFe12-xMxO19 (M = Cu and Ni) hexaferrite

Abstract

Here, we report a comprehensive study to explore the synthesis and comparative analysis of co-substituted M−type La3+/Cu2+ and La3+/Ni2+ hexaferrite (Sr1-xLaxFe12-xMxO19 where M = Cu and Ni; (x = 0.0, 0.05, 0.1, 0.15, and 0.2)) prepared through the sol–gel auto-combustion approach. X-ray diffraction (XRD) analysis shows both systems' single-phase structure of Sr hexaferrite. The structural parameters decreased as the number of substituted ions increasedas the crystal lattice contracts due to the smaller ionic radii being doped. Theaverage crystallite sizes were found using the Scherrer equation using the highest intensity peaks, and the results show nano-sized particles. The morphological structure of Sr-hexaferrite was studied using Field Effect Scanning Microscopy (FESEM). As a result, irregularly shaped particles with slight agglomeration are observed on the topography in both systems. Two absorption bands were observed in all synthesised samples' Fourier-transformed infrared spectroscopy (FTIR) spectra, supporting the ferrite's formation. These materials are a good option for high-density recording media. Both samples show high magnetic natures, which can be observed from the hysteresis loop. Overall, the room temperature magnetic parameters measured slightly increase as the dopant materials increase. The squareness ratio of the synthesizedsamples shows the uniaxial anisotropy with single magnetic domain particles. The Maxwell-Wagner and Koop model clarifies the reason the dielectric characteristics exhibit the typical behavior of ferrites.