The synthesis, characterization and sintering of nickel and cobalt ferrite nanopowders

The NiFe₂O₄ and CoFe₂O₄ ferrites were synthesized by two methods-chemical sol-gel self-combustion method and the high frequency plasma chemical synthesis and magnetic properties, crystallite size, specific surface area of synthesized products are characterized. Nanopowders synthesized in the high frequency plasma are with specific surface area in the range of (28-30) m²/g (the average particle size (38-40) nm, crystallite size ~40 nm). The ferrite nanopowders obtained by sol-gel self-combustion method have the specific surface area of (37-43) m²/g (average particle size (26-31) nm, crystallite size (10-20) nm). All synthesized nanopowders were sintered via pressure-less sintering method and magnetic properties of compacted materials were studied, as well.