Title :
Synthesis and characterization of stable colloidal Fe3O 4 particles in water-in-oil microemulsions
Author :
Lee, K.M. ; Sorensen, C.M. ; Klabunde, K.J. ; Hadjipanayis, G.C.
Author_Institution :
Kansas State Univ., Manhattan, KS, USA
fDate :
9/1/1992 12:00:00 AM
Abstract :
The authors have prepared nanometer-size magnetite particles in Aerosol OT (AOT)/water/iso-octane water-in-oil (w/o) microemulsions. The sizes of the particles in the colloids were inferred from dynamic light scattering (DLS) and were on the order of one nanometer. Those in dried samples were measured using transmission electron microscopy (TEM) and were 5-20 nm. This implies that aggregation occurs during drying. X-ray diffraction showed that the particles´ phase was consistent with magnetite. Magnetic properties were studied using a superconducting quantum interference device (SQUID) magnetometer. The colloids showed a superparamagnetic behavior and the dried samples showed a ferromagnetic behavior, supporting the size measurements using DLS and TEM, respectively
Keywords :
X-ray diffraction examination of materials; emulsions; ferromagnetic properties of substances; iron compounds; light scattering; magnetic fluids; magnetic hysteresis; magnetic properties of fine particles; nanostructured materials; particle size; superparamagnetism; transmission electron microscope examination of materials; 5 to 20 nm; Aerosol OT/water/iso-octane; SQUID magnetometer; X-ray diffraction; aggregation; colloidal Fe3O4 particles; drying; dynamic light scattering; ferromagnetic behavior; hysteresis loop; magnetic properties; nanometer-size magnetite particles; particle size; superparamagnetic behaviour; transmission electron microscopy; water-in-oil microemulsions; Aerodynamics; Aerosols; Iron; Light scattering; Magnetic properties; SQUIDs; Superconducting devices; Superconducting magnets; Transmission electron microscopy; X-ray diffraction;
Journal_Title :
Magnetics, IEEE Transactions on
