The activity performed in the framework of an Advanced Research Project funded by INFM will be outlined. A coordinated effort has been produced in order to: obtain bulk magnetic granular solids with controlled particle morphology and interfacial properties; get a detailed knowledge of the role played by magnetic interfaces on the local type and degree of magnetic order and on the spin-dependent electron-scattering processes; study the role of magnetic correlations within an assembly of weakly interacting magnetic nanoparticles on the magnetic properties and on magneto-transport phenomena. Three model systems are being analysed: a) Cu100-xCox alloys prepared either as ribbons by melt spinning and as thick films by sputtering, containing nanometer-sized magnetic particles not simply described by the superparamagnetic model owing to the effect of dipolar magnetic interactions; b) paramagnetic Au100-xFex alloys prepared either by melt-spinning or by solid-state quenching, containing very small transition-metal magnetic clusters typical cluster size: 0.4 nm; typical number of Fe atoms per cluster: 4]; c) Fe-FeO core-shell systems prepared by the Inert-Gas Condensation technique and characterised by a nanometer-sized TM core surrounded by a thin shell of ferrous oxides (either magnetite or maghemite).
Magnetic and magnetotransport properties of bulk granular magnetic systems
BISERO, Diego;RONCONI, Franco;SPIZZO, Federico;VAVASSORI, Paolo;DEL BIANCO, Lucia;
2001
Abstract
The activity performed in the framework of an Advanced Research Project funded by INFM will be outlined. A coordinated effort has been produced in order to: obtain bulk magnetic granular solids with controlled particle morphology and interfacial properties; get a detailed knowledge of the role played by magnetic interfaces on the local type and degree of magnetic order and on the spin-dependent electron-scattering processes; study the role of magnetic correlations within an assembly of weakly interacting magnetic nanoparticles on the magnetic properties and on magneto-transport phenomena. Three model systems are being analysed: a) Cu100-xCox alloys prepared either as ribbons by melt spinning and as thick films by sputtering, containing nanometer-sized magnetic particles not simply described by the superparamagnetic model owing to the effect of dipolar magnetic interactions; b) paramagnetic Au100-xFex alloys prepared either by melt-spinning or by solid-state quenching, containing very small transition-metal magnetic clusters typical cluster size: 0.4 nm; typical number of Fe atoms per cluster: 4]; c) Fe-FeO core-shell systems prepared by the Inert-Gas Condensation technique and characterised by a nanometer-sized TM core surrounded by a thin shell of ferrous oxides (either magnetite or maghemite).I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
