Synthesis and characterization of novel CoFe2O4–BaTiO3 multiferroic core–shell-type nanostructures

✍ Scribed by V. Corral-Flores; D. Bueno-Baqués; R.F. Ziolo

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 486 KB
• Volume: 58
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/j.actamat.2009.09.054

✦ Synopsis

Novel multiferroic nanostructures of cobalt ferrite-barium titanate were synthesized by a two-step wet chemical procedure, combining co-precipitation and sol-gel techniques. The fraction of cobalt ferrite in the nanostructures was varied from 20 to 60 wt.%. X-ray diffraction confirmed the presence of both the spinel and the perovskite phases, with average crystallite sizes in the range of 15-28 nm. Both the degree of tetragonality of barium titanate and the lattice parameter of cobalt ferrite significantly increased with the content of ferrite in the nanostructures, revealing a crystallographic distortion related to the shell thickness. Transmission electron microscopy data showed two-phase composite nanostructures consisting of a cobalt ferrite core surrounded by a barium titanate shell-like coating. Magnetization data showed expected ferromagnetic behavior. The multiferroic nanostructures are proposed as building blocks for higher-order multiferroic inorganic and hybrid inorganic-organic nanocomposites.