title: The influence of composition and porosity on the magnetic properties of FeCo-SiO2 nanocomposite aerogels.
abstract: FeCo-SiO2 aerogel nanocomposites with different porosity were obtained using two different sol-gel procedures: the first involves a single acidic step and gives rise to relatively dense aerogels while the second procedure allows one to obtain highly porous aerogels using urea in the second step to promote fast gelation. Samples with different loading of FeCo equimolar alloy and with different Fe : Co ratios were prepared. The magnetic properties of all the nanocomposite aerogels were extensively studied as a function of porosity and composition. Particular attention was paid to the role played by the interparticle interactions, which are mediated by the silica matrix, in determining the collective magnetic behaviour. The kind and strength of magnetic interactions are affected by both the composition and the porosity of the matrix.
authors.affiliation: Dipartimento di Scienze Chimiche and INSTM, Università di Cagliari, Cittadella Universitaria, 09042 (CA), Monserrato, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Casu
authors.forename: Maria Francesca
authors.initials: MF
authors.lastname: Casula
authors.forename: Anna
authors.initials: A
authors.lastname: Corrias
authors.forename: Andrea
authors.initials: A
authors.lastname: Falqui
authors.forename: Danilo
authors.initials: D
authors.lastname: Loche
authors.forename: Sergio
authors.initials: S
authors.lastname: Marras
authors.forename: Claudio
authors.initials: C
authors.lastname: Sangregorio
mesh_terms: D000497:Alloys / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry*; D005782:Gels / Q000737:chemistry; D007501:Iron / Q000737:chemistry*; D008280:Magnetics; D053768:Metal Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D000497:Alloys; D005782:Gels; D003035:Cobalt; D012822:Silicon Dioxide; D007501:Iron