Magnetic/SiO2 nanocomposite thin films prepared by sol-gel dip coating modified method

• Published in: Thin solid films 2011-10, Vol.520 (1), p.159-165
• Main Authors: BAIKOUSI, M, KOSTOULA, O, PANAGIOTOPOULOS, I, BAKAS, T, DOUVALIS, A. P, KOUTSELAS, I, BOURLINOS, A. B, KARAKASSIDES, M. A
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Ferrofluids; Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids); Magnetic properties and materials; Magnetic properties of monolayers and thin films; Magnetic properties of surface, thin films and multilayers; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Nanocomposites; Nanomaterials; Nanoparticles; Nanostructure; Physics; Silicon dioxide; Small particles and nanoscale materials; Sol gel process; Structure and morphology; thickness; Studies of specific magnetic materials; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Thin films
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2011.06.110

Nanocomposite thin films of Spinel Iron-Oxide and SiO2 have been prepared with sol-gel dip-coating technique involving the synthesis of a ferrofluid, which has been stabilized in absence of organic media and led to the formation of magnetic nanoparticles. Structural and morphological characteristics of the synthesized ferrofluid and the relevant derived nanocomposite films are reported, as determined from X-ray diffraction (XRD), Raman, Fourier-transform infrared, Mossbauer and Ultraviolet-visible experimental techniques. Scanning electron microscopy, atomic force and magnetic force microscopy results are also reported. The synthesized ferrofluid, composed of magnetic nanoparticles of an XRD estimated average size of 18nm, exhibit Raman spectra characteristic of a maghemite phase. These ferromagnetic nanoparticles retained their nanostructure after being inserted into the as prepared films. After heat treatment under Ar atmosphere, the maghemite nanoparticles were transformed to non-stoichiometric magnetite, providing the final composite material with useful potential application characteristics. The calcined films reported here exhibit crack-free morphology, consisting of aggregated silica/magnetic nanoparticles, with a final average size of c.a. 100nm, while the film roughness shows a maximum peak to peak of c.a. 10nm.