A study on exchange effects in hybrid cobalt ferrite-based nanomaterials to obtain new types of magnets is presented. Nowadays, alternative materials to substitute Rare Earth (RE) compounds in magnets are being researched. Cobalt ferrite (CFO) is between the spinels the one that exhibits the largest anisotropy, even if it cannot employed in magnets due to the cubic symmetry of its magnetocrystalline anisotropy. We have investigated the exchange coupling mechanism between the hard CFO with a second magnetic phase to get novel type of nanomagnets. I will illustrate several cases of hybrid core@shell (CS) nanoparticles (NPs) obtained by colloidal thermal decomposition synthesis. First, CFO and soft MnZn ferrite CS NPs have been synthesized with a morphology of spring magnet model. Second exchange-bias effects are investigated in hybrid antiferromagnetic FeCo monoxide core @ CFO shell NPs. The exchange bias can be induced by interface or intergranular exchange effects leading to the increase of the energy product. The magnetic properties of these nanostructures will be correlated with their interfacial structure and compositional properties. This research was supported by EU-FP7 NANOPYME (n. 310516) and EU- H2020 AMPHIBIAN Projects (n. 720853).
Novel developments in hybrid ferrite-based hard nanomaterials
2018
Abstract
A study on exchange effects in hybrid cobalt ferrite-based nanomaterials to obtain new types of magnets is presented. Nowadays, alternative materials to substitute Rare Earth (RE) compounds in magnets are being researched. Cobalt ferrite (CFO) is between the spinels the one that exhibits the largest anisotropy, even if it cannot employed in magnets due to the cubic symmetry of its magnetocrystalline anisotropy. We have investigated the exchange coupling mechanism between the hard CFO with a second magnetic phase to get novel type of nanomagnets. I will illustrate several cases of hybrid core@shell (CS) nanoparticles (NPs) obtained by colloidal thermal decomposition synthesis. First, CFO and soft MnZn ferrite CS NPs have been synthesized with a morphology of spring magnet model. Second exchange-bias effects are investigated in hybrid antiferromagnetic FeCo monoxide core @ CFO shell NPs. The exchange bias can be induced by interface or intergranular exchange effects leading to the increase of the energy product. The magnetic properties of these nanostructures will be correlated with their interfacial structure and compositional properties. This research was supported by EU-FP7 NANOPYME (n. 310516) and EU- H2020 AMPHIBIAN Projects (n. 720853).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
