Electrochemical Synthesis of New Magnetic Mixed Oxides of Sr and Fe:  Composition, Magnetic Properties, and Microstructure

Abstract

An electrochemical method for the preparation of magnetic nanoparticles of new Sr−Fe oxides is presented in this work. It consists of the electrolysis of nitrate or chloride solutions with Sr2+ and Fe3+ salts using commercial Fe electrodes. Magnetic materials are collected as precipitates from nitrate media in the pH range 1−3 and from chloride media within the pH range 1−12. The presence of 100−300 ppm aniline in acidic nitrate media yields a decrease in energy cost and particle size. Inductively coupled plasma analysis of materials and energy-dispersive X-ray spectrometry of single particles confirm that they are composed of mixed oxides of Sr and Fe. All synthesized materials crystallize as inverse cubic spinels, usually with intermediate structures between magnetite and maghemite. They are formed by nanoparticles with average sizes from 2 nm to ∼50 nm, as observed by scanning electron microscopy. The electrogenerated mixed oxides have higher saturation magnetization, but lower remanent magnetization and coercive field, than commercial strontium hexaferrite with micrometric particle size.

Hydrothermal Synthesis of SrFe12O19 and Its Characterization

“…The commercial demand of strontium hexaferrite increases continuously, because of its significant magnetic properties and higher coercitivity than barium hexaferrite [5].…”

Copper–cobalt heterobimetallic ceramic oxide thin film deposition: Synthesis, characterization and application of precursor

“…The unique electronic and magnetic properties obtained when combining two metals in an oxide matrix have been well studied [11,12].…”

Magnetic field-induced growth and self-assembly of cobalt nanocrystallites

“…[7][8][9][10] Various approaches have been developed to prepare nanoscale magnetic materials. [11][12][13][14] For example, cobalt nanoparticle rings 15 and nanodisks 16 were fabricated by metal carbonyl pyrolysis. However, little attention has been paid to the effect of a magnetic field on the nucleation and growth process of the magnetic materials and on the movement and self-assembly behavior of magnetic nanocrystallites.…”