title: Microwave-assisted nonaqueous sol-gel deposition of different spinel ferrites and barium titanate perovskite thin films.
abstract: Rapid and selective heating of solvents by microwave irradiation coupled to nonaqueous sol-gel chemistry makes it possible to simultaneously synthesize metal oxide nanoparticles within minutes and deposit them on substrates. The simple immersion of substrates, such as glass slides, in the reaction solution results after microwave heating in the deposition of homogeneous porous thin films whose thickness can be adjusted through the precursor concentration. Here we use such a microwave-assisted nonaqueous sol-gel process for the formation of various spinel ferrite MFe2O4 (M = Fe, Co, Mn, Ni) and BaTiO3 nanoparticles and their deposition as thin films. The approach offers high flexibility with respect to controlling the crystal size by adjusting the reaction time and/or temperature. Based on the example of CoFe2O4 nanoparticles, we show how the crystal size can carefully be tuned from 4 to 8 nm, resulting in a continuous change of the magnetic properties.
authors.affiliation: ETH Zurich, Department of Materials. Laboratory for Multifunctional Materials, Wolfgang-Pauli Strasse 10, CH-8093 Zürich.
authors.forename: Martin
authors.initials: M
authors.lastname: Kubli
authors.forename: Li
authors.initials: L
authors.lastname: Luo
authors.forename: Idalia
authors.initials: I
authors.lastname: Bilecka
authors.forename: Markus
authors.initials: M
authors.lastname: Niederberger