Cobalt carbide-based nanoparticle permanent magnet materials

A method of making crystalline ferromagnetic nanoparticles, said nanoparticles comprising cobalt carbides as Co2C and Co3C phases, said nanoparticles having a coercivity value greater than or equal to 500 Oe, said method comprising the steps of:

• chemically reducing one or more cobalt salts in a liquid polyol medium comprising one or more rare earth moieties, whereby a reaction precipitate is formed, the precipitate comprising said nanoparticles;
• collecting the reaction precipitate;
• and
• rinsing and drying the precipitate to yield said nanoparticles.

A method of making crystalline ferromagnetic nanoparticles, said nanoparticles comprising iron carbides as Fe2C and Fe3C phases, said nanoparticles having a coercivity value greater than or equal to 500 Oe, said method comprising the steps of:

• chemically reducing one or more iron salts in a liquid polyol medium comprising one or more rare earth moieties, whereby a reaction precipitate is formed, the precipitate comprising said nanoparticles;
• collecting the reaction precipitate;
• and
• rinsing and drying the precipitate to yield said nanoparticles.

A method of making crystalline ferromagnetic nanoparticles, said nanoparticles comprising a multiphase mixture and/or admixture of iron cobalt carbides, said nanoparticles having a coercivity value greater than or equal to 500 Oe, said method comprising the steps of:

• chemically reducing one or more iron and cobalt salts in a liquid polyol medium comprising one or more rare earth moieties, whereby a reaction precipitate is formed, the precipitate comprising said nanoparticles;
• collecting the reaction precipitate;
• and
• rinsing and drying the precipitate to yield said nanoparticles.