A novel method for synthesizing narrow particle size distribution of holmium–doped strontium hexaferrite by sol-gel auto-combustion

Abstract

In this study, a new technique put in to the sol-gel auto-combustion method which is the preparation of solutions and treatment of products by using ultrasonic liquid sonicate. Different atomic concentrations of Holmium-doped strontium hexaferrite (SrFe12−xHoxO19) been synthesized by the conventional sol-gel auto-combustion method. This new technique estimates as a novel method which escalates the amount of Ho+3 present in strontium hexaferrite of produced powder by 500% compared to the conventional method when Ho+3 substitution was 15% of atomic weight. Characterization of produced powders, porosity, unit cell volume, and lattice parameters were tested and calculated from x-ray diffraction. Morphology, particle size distribution, and shape of nanoparticles were analyzed by field emission scanning electron microscope. Primary particle size and particle size distributions were studied by transmission electron microscope. The purity and elemental composition of products were tested by energy dispersive spectrometer. Bulk density, crystallinity, and purity increased with decreased crystal size and porosity when nanoparticles were treated by ultrasonic method. Morphology, purity, narrow particle size distribution, and nanoparticles with isomorphic geometry can be controlled with Ho+3 substitution by 15% of atomic weight when powder is produced by this novel method. This new technique provides an improved new method for narrowing particle size distribution, increasing density, and substitution limit of rare earth ions to hexaferrites.