Microstructure and magnetic properties of substituted (Cr, Mn) - cobalt ferrite nanoparticles

Enhanced magnetic properties of doped cobalt ferrite nanoparticles by virtue of cation distribution

“…In our present study we are able to synthesized particles having diameter around 11 nm to 14 nm with high crystallinity keeping sintering temperature 550 0 C for 30 minutes which are quite low and quick respectively.Almost similar kind of sintering temperature resulted in higher crystallite sizes of cobalt ferrite prepared by citrate precursor method[36]. In addition, similar value of saturation magnetization M s have been reported for CoFe 2 O 4 nanoparticles prepared under a simple hydrothermal condition[37], single domain CoFe 2 O 4 nanoparticles synthesized by coprecipitation method[38].Thus it is observed that doping of Ni and Mn in nanocrystalline cobalt ferrite can enhance the magnetic properties by changing the cation distribution between the two sublattices. Calculated magnetic moment using our proposition of cation distribution perfectly matches with experimental observation which also corroborate with Rietveld analysis.…”

Structural phase transition of as-synthesized Sr–Mn nanoferrites by annealing temperature

“…The small coercivity proves that the agglomeration of nanocrystallites causes increase in magnetic coupling and higher magnetization where surface effects are dominant, therefore the surface spins also affect the magnetization and anisotropy energy [4][5][6]. The increase in H c and decrease in M s with T lead to increase in anisotropy constant K (Fig.…”

“…Co-Cr-, Co-Mn-. , Mn-Ni-, Mn-Znand Cu-Al-Cr-nanoferrite samples were annealed at different temperatures and characterized by using different techniques [4][5][6][7][8][9]. The obtained results proved that the sample properties were varied with annealing temperature range.…”

Temperature dependence of magnetic properties of heat treated cobalt ferrite

“…Both heat treatment and cation substitution can also affect the oxygen stoichiometry which in turn affects the exchange interaction since the cations are indirectly coupled through the oxygen anions in the crystal lattice. Although there have been extensive investigations on improving the properties of cobalt ferrite based materials by cation substitutions, [2][3][4][5][6][7] there has not been a commensurate level of investigation on enhancing the properties by heat treatment. Nevertheless, it has been shown that heat treatment can be used to control the magnetic properties of cobalt ferrite as desired.…”