Bulk anisotropic exchange-spring magnets and method of producing the same

A method of preparing an anisotropic permanent magnet nanocomposite, the method comprising:

• melting a precursor alloy having a hard magnetic phase and a magnetically soft phase, the hard magnetic phase comprising less than a stoichiometric amount of a rare earth metal or a noble metal;
• casting the melted precursor alloy into flakes;
• milling the casted flakes into a powder;
• and
• pressure crystalizing the powder by:
• pressurizing and heating the powder at a crystallization pressure ranging from about 0.5 GPa to about 3 GPa and at a crystallization temperature over a pressurizing time, wherein the powder is pressurized at a rate of about 200 MPa/min;
• holding the powder at the crystallization temperature and the crystallization pressure over a hold time to promote crystal growth;
• and
• rapidly quenching the crystal growth to a temperature less than about 200° C. in less than about a minute.