Ferrofluids are extensively used for the study of magnetic domain
structures in magnetic tapes, rigid and floppy disks, magneto-optical
disks, crystalline and amorphous alloys, garnets, steels and geological
Commercial applications include the quality control of magnetic
recording media and the identification of micro-defects in steel.
Ferrofluid is applied to the magnetic tape, disk or other specimen
so that a thin layer of ferrofluid covers the surface. When the
carrier liquid evaporates, the particles congregate at the domain
boundaries. These appear as dark lines in visible light and can
be viewed with a microscope. A small external magnetic field can
be applied to the specimen to enhance the contrast of the pattern.
The EMG series of ferrofluids, which includes both water and mineral
oil based fluid, has been developed specifically for this purpose.
Domain detection kits which include samples of different ferrofluid,
wetting agent and solvent are also available.
| Users of ferrofluid
for domain detection include many audio and video tape manufacturers,
TV and recording studios, forensic science laboratories and
research institutions. A range of water-based and mineral oil-based
domain detection fluids are available.
Ferrofluid | Vacuum
Feedthroughs | Thermoelectric Modules
Contract Manufacturing | Literature
Rack | Specialty Seals
Inertia Dampers | Electron