title: "Magnetic force microscopy and energy loss imaging of superparamagnetic iron oxide nanoparticles".
abstract: We present quantitative, high spatially resolved magnetic force microscopy imaging of samples based on 11 nm diameter superparamagnetic iron oxide nanoparticles in air at room temperature. By a proper combination of the cantilever resonance frequency shift, oscillation amplitude and phase lag we obtain the tip-sample interaction maps in terms of force gradient and energy dissipation. These physical quantities are evaluated in the frame of a tip-particle magnetic interaction model also including the tip oscillation amplitude. Magnetic nanoparticles are characterized both in bare form, after deposition on a flat substrate, and as magnetically assembled fillers in a polymer matrix, in the form of nanowires. The latter approach makes it possible to reveal the magnetic texture in a composite sample independently of the surface topography.
authors.affiliation: Italian Institute of Technology (IIT)–Nanobiotechnology Department, Via Morego 30 – I-16163 Genova, Italy. bruno.torre@iit.it
authors.forename: Bruno
authors.initials: B
authors.lastname: Torre
authors.forename: Giovanni
authors.initials: G
authors.lastname: Bertoni
authors.forename: Despina
authors.initials: D
authors.lastname: Fragouli
authors.forename: Andrea
authors.initials: A
authors.lastname: Falqui
authors.forename: Marco
authors.initials: M
authors.lastname: Salerno
authors.forename: Alberto
authors.initials: A
authors.lastname: Diaspro
authors.forename: Roberto
authors.initials: R
authors.lastname: Cingolani
authors.forename: Athanassia
authors.initials: A
authors.lastname: Athanassiou