Address: | Laboratory Microwave Magnetics, 72 Tzarigradsko chaussee blvd, 1784-Sofia |
Country: | Bulgaria |
Website: |
Organisation type: | Academic |
Storage activities: | characterization of nanosized ferroxide powders for optical applications |
Profile: | The Microwave Magnetic Laboratory has long years of experience in studying the processes of electromagnetic radiation interaction with magnetic media. The rapid development of the nanotechnologies allowed the preparation of nanosized magnetic particles, which in turn opened possibilities for applications of monodomain and superparamagnetic hybrid structures in electronic components. The laboratory’s research activities have always been of interdisciplinary nature and in the past year were focused on the preparation of monodomain particles of Ba hexaferrite, which is a model highly anisotropic crystalline structure. A methodology was developed allowing the preparation of hexagonal ferrite powders with average particles size of 100 – 300 nm. These were used to developed composite coatings containing two magnetic phases encapsulated in a non-magnetic polymer matrix. The interaction was studied of these structures with microwave electromagnetic fields in a wide frequency range. Magnetic shielding structures were fabricated with attenuation exceeding 15 dB in the cm-range. Interest for applications was showed by Sky-Gate Company. Data were obtained on the blocking temperature of nanosized magnetite and on the structural changes on the nano-particle’s surface, which determine the “superparamagnetic limit” for appli-cation in electronic components. These data may be of importance in the minia-turization of magnetic recording nano-elements. A new field in the laboratory’s research activities was studying of ferrofluids and the contribution of superparamagnetic nanoparticles to the effect of hyperthermia caused by the fluid interaction with RF electromagnetic fields. Based on superparamagnetic magnetite, functional fluids were prepared with controlled hyperthermia temperature. The magnetite material was the object of a patent obtained in 2008. |
Email: | (Dept Head) |
Tel: | +359 2 979 5909 |
Fax: | +359 2 975 3201 |