Characterization of mesoporous nanostructured cobalt ferrite foams fabricated by microwave and conventional sintering routes

Cobalt ferrite nanopowders with an average particle size of 50 nm were synthesized by a modified Pechini type sol-gel method. Obtained powder was subjected for fabrication of magnetic foams by using microwave and conventional sintering approaches coupled by space holder method. Carbamide was used as space holder material. Samples were characterized by X-ray diffraction, stereomicroscope, scanning and transmission electron microscope, nitrogen gas adsorption-desorption, and vibration sample magnetometer analyses. The results revealed that microwave sintering offered magnetic foams with surface area of 5.21 m(2)/g which is four times greater than the samples obtained by conventional sintering. Such a mesoporous nanostructure was achieved only after 5 min of microwave sintering which yielded monolith foams with sufficient strength and grain growth suppression of nanostructure. Moreover, magnetic studies indicated that magnetic parameter of squareness ratio for microwave sintered foams is twice greater than that of conventionally sintered foams.