Patent ID: 10319502

Abstract:
Magnetic particles (100) have a particle size (134) of 500 nm or less and include a core (110) and a polymer coating (120) that surrounds and encapsulates the core (110). The core (110) includes a metal, metal alloy, or metal oxide of at least one metal such as B, Mg, Al, Mn, Co, Ni, Cu, Fe Sm, Yb, Dy, Gd or Er and Nb. The magnetic core (100) is a polycrystalline particle and is a superspin glass magnetic material, having a coercivity greater than zero and a magnetic remenance greater than zero at room temperature. Above room temperature and at low field, the magnetic moment of these superspin glass magnetic materials increases with temperature. An in situ hydrolysis/precipitation method from precursor metal salts is used to form the polymer-encapsulated magnetic particles (100).